We need a sample size of at least 139 to be 95% confident that the sample mean IQ score is within 5 points of the true mean IQ score.
What is mean?
In statistics, the mean (also known as the arithmetic mean or average) is a measure of central tendency that represents the sum of a set of numbers divided by the total number of numbers in the set.
To find the required sample size, we can use the formula for the margin of error:
Margin of Error = z * (σ / √n)
Where z is the z-score for the desired level of confidence, σ is the population standard deviation, and n is the sample size.
We want the margin of error to be 5 IQ points, and we want to be 95% confident that the sample mean is within this margin of error of the true population mean. The z-score for 95% confidence is 1.96.
5 = 1.96 * (12 / √n)
Solving for n, we get:
n = (1.96 * 12 / 5)²
n ≈ 138.3
Therefore, we need a sample size of at least 139 to be 95% confident that the sample mean IQ score is within 5 points of the true mean IQ score.
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Find the area of the shape shown below.
Answer:
8 units²
Step-by-step explanation:
What you have is a square with two triangles. We will break them apart, calculate the area and then add them together.
Square: A = l · w
2 · 2 = 4 un²
Triangle: A = (b · h) ÷ 2
(2 · 2) ÷ 2 = 2 un²
4 un² + 2 un² + 2 un²
8 un²
Help!!!
The amount of force, F, needed to lift an object using a lever varies inversely as the length, l, of the lever. When a 24-inch lever is used, a force of 240 pounds is needed. How much force is needed if a 36-inch long lever is used?
I already know A. 120 pounds is wrong
A. 120 pounds XXX
B. 160 pounds
C. 252 pounds
D. 360 pounds
Answer:
F = 160 pounds
B. 160 pounds
Step-by-step explanation:
F = k / l
Where,
F = amount of force needed
l = length of the lever
k = constant of proportionality
F = 240 when l = 24 inch
F = k / l
240 = k / 24
Cross product
240*24 = k
k = 5,760
Find F when l = 36 inch
Recall, k = 5,760
F = k / l
= 5,760 / 36
= 160
F = 160 pounds
The correct answer is B. 160 pounds
The variation is an inverse variation.; so, 160 pounds of force is needed for a 36-inch long lever
Given that F varies inversely as L, the variation is represented as:
\(F\ \alpha\ \frac 1L\)
Express as an equation
\(F\ =\ \frac kL\) -- where k represents the constant of variation
Make k the subject
\(k =FL\)
When F = 240, L = 24.
So, we have:
\(k =240 \times 24\)
\(k =5760\)
Substitute 5760 for k in \(k =FL\)
\(5760 = FL\)
When L = 36, we have:
\(5760 = 36F\)
Divide both sides by 36
\(160 = F\)
Rewrite as:
\(F = 160\)
Hence, 160 pounds of force is needed for a 36-inch long lever
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The sound level measured in a room by a person watching a movie on a home theater system varies from 60 dB during a quiet part to 100 dB during a loud part. Approximately how many times louder is the latter sound
Answer:
The sound in a loud part of the room is 10000 times louder than sound in a quiet part of the same place.
Step-by-step explanation:
The acoustic intensity sound is a logarithmic function whose form is:
\(L = 10\cdot \log_{10}\left(\frac{I}{I_{o}} \right)\)
Where:
\(L\) - Acoustic intensity sound, measured in decibels.
\(I_{o}\) - Reference sound intensity, measured in watts per square meter.
\(I\) - Real sound intensity, measured in watts per square meter.
Sound intensity is now cleared:
\(10^{\frac{L}{10} } = \frac{I}{I_{o}}\)
The ratio of the sound intensity in a loud part to the sound intensity in a quiet part is:
\(\frac{I_{100}}{I_{60}} = \frac{10^{\frac{100\,dB}{10} }}{10^{\frac{60\,dB}{10}}}\)
\(\frac{I_{100}}{I_{60}} = \left(10^{100\,dB-60\,dB}\right)^{\frac{1}{10} }\)
\(\frac{I_{100}}{I_{60}} = (10^{40\,dB})^{\frac{1}{10} }\)
\(\frac{I_{100}}{I_{60}} =10^{4}\)
The sound in a loud part of the room is 10000 times louder than sound in a quiet part of the same place.
A coin weighs 4/15 ounces. A different coin weighs 1/15 ounces. How much do the two coins weigh together? Write your answer as a fraction in simplest form.
Answer:
1/3
Step-by-step explanation:
4/15 + 1/15 = 5/15
simplified its 1/3
2 to the power of =32
I need it to day
Find the value of each variable.
Answer:
Step-by-step explanation:
The sum of exterior angles in a quadrilateral is always 360 degrees.
So, 2x+x+4x+3x=10x=360
Soling for x, we get x=36 degrees.
A college graduate expects to earn a salary of $55,000 during the first year after graduation and receive a 3% raise every year after that. What is the total income he will have received after ten years?
Answer:
$73915.40
Step-by-step explanation:
→ Find the multiplier
( 3 + 100 ) ÷ 100 = 1.03
→ Multiply by principal amount and raise it to the power of years
55000 × 1.03¹⁰ = 73915.40
Answer: $630,513.36
Step-by-step explanation:
Making a Formula for His Salary on a Given YearLet's make a table of values to see how much he earns every year after graduation.
1 year -> $55,000
2 years -> 55,000 * 103% = $56,650
3 years -> 56,650 * 103% = 55000 * 103% * 103% = $58,349.50
4 years -> 58349.50 * 103% = 55,000 * 103% * 103% * 103% = 55000(1.03)³
Here, we see that every year, he gets 103% of what he got the previous year, which is also 1.03 times his previous salary.
We also see that we multiply 55000 by 1.03 three times in the fourth year, and two times in the third year. This means that we multiply 55000 by 1.03 n-1 times.
Using this, let's generalize this for n.
n years -> \(55000(1.03)^{n-1}\)
Finding the Sum after Ten YearsWe are trying to find his total income after ten years, or the sum of his salary from year 1 to year 10. We can represent this in sigma notation like this
\(% Adjusted limits of summation$\displaystyle\sum_{n=1} ^{10} 55000(1.03)^{n-1}$\)
This essentially translates to the sum of the first ten terms in the sequence \(55000(1.03)^{n-1}\), starting at n=1.
Since this is a geometric sequence, or a sequence where we need to multiply by the same number to get to the next term, we can find the sum using the sum of geometric series formula. This formula is as follows:
\(S_n=a_1\frac{1-r^n}{1-r}\)
where \(S_n\) is the sum of the first n terms, \(a_1\) is the first term, r is the common ratio, and n is the number of terms. In this question, \(S_n\) is the total income after n years, \(a_1\) is his salary after the first year, r is how much his salary increases by each year, and n is the number of years we are calculating the sum for.
\(a_1\) -> 55000
r -> 1.03
n -> 10
Now that we have the values for each variable, let's plug them in and solve
\(S_{10}=55000(\frac{1-1.03^{10}}{1-1.03})\\S_{10}=630513.36\)
The total income he will have received after ten years is $630,513.36.
Solve the following problems using the Polygon Interior Angle Sum Theorem and Polygon Exterior Angle Sum Theorem.
Sum of the measures of the interior angles of the regular nonagon
Measure of each interior angle of the regular nonagon
Measure of each exterior angle of the regular nonagon
a) The sum of the measures of the interior angles of the regular nonagon is given by S₉ = 1260°
b) The measure of each interior angle of the regular nonagon is a = 140°
c) The measure of each exterior angle of the regular nonagon is b = 40°
Given data ,
Sum of the measures of the interior angles of a regular nonagon:
The Polygon Interior Angle Sum Theorem states that the sum of the measures of the interior angles of a polygon with n sides is given by the formula:
Sum of interior angles = (n - 2) * 180°
For a nonagon, which has 9 sides, we can plug in n = 9 into the formula:
Sum of interior angles = (9 - 2) * 180
Sum of interior angles = 7 * 180
Sum of interior angles = 1260°
So, the sum of the measures of the interior angles of a regular nonagon is 1260°
Measure of each interior angle of a regular nonagon:
Since a regular nonagon has 9 sides, we can divide the sum of the interior angles (which we calculated as 1260 degrees) by the number of sides to find the measure of each interior angle:
Measure of each interior angle = Sum of interior angles / Number of sides
Measure of each interior angle = 1260 / 9
Measure of each interior angle = 140°
So, the measure of each interior angle of a regular nonagon is 140°
Measure of each exterior angle of a regular nonagon:
The Polygon Exterior Angle Sum Theorem states that the sum of the measures of the exterior angles of a polygon with n sides is always 360°
Since a regular nonagon has 9 sides, we can divide 360 degrees by the number of sides to find the measure of each exterior angle:
Measure of each exterior angle = 360 / Number of sides
Measure of each exterior angle = 360 / 9
Measure of each exterior angle = 40°
Hence , the measure of each exterior angle of a regular nonagon is 40°
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Kayden wants to ride his bicycle 29.5 miles this week. He has already ridden 13 miles.
If he rides for 3 more days, write and solve an equation which can be used to
determine m, the average number of miles he would have to ride each day to meet his
goal.
Answer:
5.5
Step-by-step explanation:
29.5-13=16.5 16.5÷3=5.5
pleaseeeee help me with this question
Answer:
Step-by-step explanation:
smallest value=-240
critical number=(4.5,-240)
relative maximum=200
critical number=(-0.5,200)
relative minimum=-240
largest value=200
Translate this inequality as sentence :- x + 5 ≥ 10
Answer:
Let's solve your inequality step-by-step.
x+5≥10
x+5−5≥10−5
x≥5
Step-by-step explanation:
\( \longmapsto\sf x + 5 \geqslant 10\)
\( \longmapsto \sf x \geqslant 10 - 5\)
\( \longmapsto\bf x \geqslant 5\)
What is the perimeter of this rectangle?
Answer:
6\(\sqrt{17}\) or 24.738634
Step-by-step explanation:
We can use the Pythagorean theorem to find the length of the sides. We will only need to find the length of AB and AD, as AB = DC and AD = BC.
The picture shows the Pythagorean theorem being used to find AB and AD.
AB = \(\sqrt{17}\)
AD = \(\sqrt{68}\)
Now we can find the perimeter
2(\(\sqrt{17}\)) + 2(\(\sqrt{68}\)) = 6\(\sqrt{17}\)
Which of the number lines is the correct graph for the inequality x ≥ 9?
Answer:
graph D.
Step-by-step explanation:
The inequality that is being shown in the question means that the value of x is equal to or greater than 9. Greater values are represented as all of the values to the right of a certain number. On a number line "equal to" is represented by a closed circle. Therefore, with this knowledge we can see that out of all of the provided options the only one that follows these set of rules would be graph D.
(Please help me!!) A polygon is shown on the graph:
If the polygon is translated 4 units down and 5 units right, what will the coordinates of the new image be? Use prime notation in expressing the new coordinates.
Answers:
A ' = (-1, 1)B ' = (-1, -2)C ' = (3, -2)D ' = (3, 2)===================================
Explanation:
When we translate 4 units down, we're subtracting 4 from the y coordinate. Point A(-6,5) moves to (-6,1) after applying this translation.
Then we add 5 to the x coordinate because we're shifting 5 units to the right. This means (-6,1) moves to (-1,1) which is the location of point A'.
The other three points follow the same pattern: add 5 to the x coordinate, subtract 4 from the y coordinate.
The translation rule can be written as \((x,y) \to (x+5, y-4)\)
Solve the system of equations using the substitution or elimination method.
y = 4x - 7
4x + 2y = -2
.
Show your work
Correct x and y
The solution to the system of equations is x = 1 and y = -3.
To solve the system of equations using the substitution or elimination method, let's start with the substitution method.
Given equations:
y = 4x - 7
4x + 2y = -2
We'll solve equation 1) for y and substitute it into equation 2):
Substituting y from equation 1) into equation 2):
4x + 2(4x - 7) = -2
4x + 8x - 14 = -2
12x - 14 = -2
Now, we'll solve this equation for x:
12x = -2 + 14
12x = 12
x = 12/12
x = 1
Now that we have the value of x, we can substitute it back into equation 1) to find y:
y = 4(1) - 7
y = 4 - 7
y = -3
Therefore, the solution to the system of equations is x = 1 and y = -3.
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Sand is being dumped from a conveyor belt and forms a conical pile. Assuming that the height of this cone is always exactly 3 times the size of the radius of its base, and that thesand is added at the rate of 10 m^3/min, how fast is the height increasing when the pile is15 m high?
Answer:
dh/dt = 0.4 m/min
Step-by-step explanation:
The volume of the cone is:
V(c) = (1/3)*r² *h if always h = 3r then r = h/3
The volume of the cone as a function of h will be:
V(h) = (1/3)* (h/3)²*h
V(h) = (1/27)*h³
The increasing rate of the volume is equal to the rate of sand added the:
D(V)/dt = (1/27)*3*h²*dh/dt
D(v) / dt = 10 m³/min
h = 15 m and dh/dt is the rate of increasing of the height
By substitution
10 m³/min = ( 1/9)* 225 * dh/dt (m²)
dh/dt = 90 / 225 m/min
dh/dt = 0.4 m/min
PLEASE HELP ME FAST!!!!!!
WILL MARK BRAINLIEST!!!!!!!
Phillip is ordering an ice cream sundae that consist of ice cream and
toppings. He can get either chocolate or vanilla as his ice cream. For his
toppings, he can get either sprinkles, almonds, or hot fudge. How many
different ways can Phillip order ice cream?
EDITED: Answer: Phillip can order 12 different ways of ice cream.
Step-by-step explanation:
Ahem.
He can only have Vanilla or Chocolate. So let's pet them in a separate Row.
Vanilla
With SprinklesWith AlmondsWith Hot FudgeWith Sprinkles and AlmondsWith Sprinkles and Hot FudgeWith Almonds and Hot FudgeChocolate
1.With Sprinkles
2.With Almonds
3.With Hot Fudge
4.With Sprinkles and Almonds
5.With Sprinkles and Hot Fudge
6.With Almonds and Hot Fudge
A telemarketing company is conducting a study of new calling scripts. A group of 75 employees will be randomly
assigned to three new scripts. The study designer numbers the subjects from 01 to 75, and uses a table of random
digits to select 50 unique, two-digit numbers in the range 01-75. The 25 subjects corresponding to the first 25
random two-digit numbers will be assigned to script 1, the second 25 to script 2, and the 25 remaining subjects to
script 3. Select the statement that best describes the composition of the treatment groups.
O The treatment groups should be comparable, because characteristics of the subjects should be roughly
equivalent among the three groups.
O The treatment groups should be comparable, because there are 25 subjects in each group
The treatment groups should be comparable, because there are a relatively large number of subjects in each
group.
O The treatment groups will not be comparable
The treatment groups should be comparable, and any differences in the outcomes of the telemarketing calls can be attributed to the different scripts and not to any systematic differences in the characteristics of the subjects.
The statement that best describes the composition of the treatment groups in this scenario is: "The treatment groups should be comparable because characteristics of the subjects should be roughly equivalent among the three groups."
Randomly assigning the subjects to the three new scripts using a table of random digits helps ensure that there is no bias in the selection process and that the characteristics of the subjects should be roughly equivalent among the three groups.
The fact that there are 25 subjects in each group and a relatively large number of subjects in total (75) also supports the comparability of the treatment groups.
Thus, the treatment groups should be comparable, and any differences in the outcomes of the telemarketing calls can be attributed to the different scripts and not to any systematic differences in the characteristics of the subjects.
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Answer: Its A
Step-by-step explanation: i got it right on edge 2023, keep going u got thisss <3
Please help asap! really important!!
Answer:
4th graph
6th graph
3rd graph
Step-by-step explanation:
Linear = y = x + 3
it is 4th graph
when you substitute x = 0 y is 3
and when y = 0 x is -3
Quadratic = y = 3x^2
It is 6th graph
for both positive and negative values of x, y is rapidly increasing
Exponential = y = 3^x
it is 3rd graph
for x = 0 y value is 1 because 3^0 = 1
for positive values of x, y is exponentially rising
for negative values of x it is nearly almost touches zero
What is the value of x?
Really need help please. When u finish this one I need help with more
Answer:
Step-by-step explanation:
Similar triangles have the same shape but different sizes.
A is incorrect. We don't know the length of the sides, or if it is equilateral so we can't say that fg/lm=fh/ln
B is correct. FH and LN may be different sizes but they are similar
C is correct. Since the triangles are similar the angles are similar.
D is incorrect. The triangle is the same shape, not neccesarily the same size
E is correct. See C for explanation.
I also need help with these
Answer:
Triangles = 4
Rectangles = 2
Step-by-step explanation:
Triangle.
8/2 = 4 . ratio = 4:1 or fraction form as 4
Rectangle.
4/2 = 2. ratio = 2:1 or fraction form as 2
If my answer is incorrect, pls correct me!
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When 2 consecutive prime numbers are subtracted we get the difference 6 and when they are multiplayed we get the number 3128. find the numbers.
Answer:
it is impossible as when we multiply two prime numbers other than 2 we get the number odd but 3128 is an even number
Step-by-step explanation:
An engineer is monitoring the liquid level in two tanks as they are being filled. The volume of the tank A after x minutes is represented by the equation y=75x +110. For tank B the engineer has created a table, shown below, from measurements taken while the tank is being filled
The two tanks differ in terms of Filling rates and initial volumes.
We can work with the equation for tank A, which represents a linear relationship between the volume of liquid in the tank (y) and the time it has been filling (x).
The equation y = 75x + 110 tells us that the tank A is filling at a constant rate of 75 units per minute, starting with an initial volume of 110 units.
To analyze the data for tank B, we would need to know the volumes of the tank at different times as it is being filled.
If the relationship for tank B is also linear, we could find the equation that represents it by using two points from the table and the slope-intercept form of a linear equation (y = mx + b). Once we have both equations, we can compare them to see how the two tanks differ in terms of filling rates and initial volumes.
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Determina el valor de la variable de la siguiente ecuación.
6
x
−
15
=
3
x
+
10
The value of the variable in the given equation is x = 25/3.
To determine the value of the variable in the given equation, we need to solve it.
The equation is:
6x - 15 = 3x + 10
To simplify the equation, we can start by subtracting 3x from both sides:
6x - 3x - 15 = 3x - 3x + 10
This gives us:
3x - 15 = 10
Next, we can add 15 to both sides of the equation:
3x - 15 + 15 = 10 + 15
This simplifies to:
3x = 25
Finally, to isolate x, we divide both sides of the equation by 3:
(3x)/3 = 25/3
This gives us:
x = 25/3
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the kindergarten section of lehigh valley has 12 classerooms . if each class room can a accommodate less than 15 kides how many kides the kindergartner section accommodate in all , write an slove an inequality ?
If each classroom can accommodate less than 15 kids, then we can assume that the maximum number of kids in each classroom is 14 (since 15 is not allowed). Therefore, the maximum number of kids in all 12 classrooms would be:
Max number of kids = 14 kids/classroom x 12 classrooms = 168 kids
So the kindergarten section can accommodate a maximum of 168 kids.
We can write this as an inequality as follows:
Let K be the number of kids in the kindergarten section. Then:
K ≤ 168
This inequality says that the number of kids in the kindergarten section (K) is less than or equal to 168. As long as the number of kids is less than or equal to 168, the kindergarten section can accommodate them all.
4) The total of the building is $35. The discount is 60%. What is the total? A) $14 B) $69 C) $58 d) $29 4) El total del edificio es de $ 35. El descuento es del 60%. ¿Cual es el total?
Original total of building = $35
Discount = 60% = 60/100 = 0.6 ( decimal form)
First, multiply the original total (35) by the discount in decimal form
35 x 0.6 = 21
Subtract it to the original total
35-21= $14
Silver Stirrup Horse Rescue is going to paint the front of the big red barn. The triangular top portion of the barn is 20 feet across and 8 feet tall. The rectangular bottom portion is also 20 feet across, buts it’s 13 1/2 feet tall. The rescue will use extra-double gallons of paint that cover over 100 sq ft each.
How many gallons of paint does the rescue need to cover the entire front of the barn?
Write your answer as A Whole Number, Proper fraction or Mixed Number
fine the nth term of 11,13,15,17
The nth term of 11,13,15,17 is,
⇒ T (n) = 9 + 2n
Given that;
The sequence is,
11, 13, 15, 17, ....
Here, Common difference is,
13 - 11 = 2
15 - 13 = 2
Hence, Sequence is in Arithmetic sequence.
So, the nth term of 11,13,15,17 is,
⇒ T (n) = a + (n - 1)d
⇒ T (n) = 11 + (n - 1) 2
⇒ T (n) = 11 + 2n - 2
⇒ T (n) = 9 + 2n
Thus, The nth term of 11,13,15,17 is,
⇒ T (n) = 9 + 2n
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Could someone help with me his before I go to sleep and I hope when I wake up the answer is here pls