Assume that we want to estimate the mean IQ score for the population of statistics students. How many statistics students must be randomly selected for IQ tests if we want 95% confidence that the sample mean is within 3 IQ points of the population mean? The Standard Deviation is 15.

Answers

Answer 1

Answer:

97 students must be randomly selected for IQ tests.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

The Standard Deviation is 15.

This means that [tex]\sigma = 15[/tex]

How many statistics students must be randomly selected for IQ tests if we want 95% confidence that the sample mean is within 3 IQ points of the population mean?

This is n for which M = 3. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]3 = 1.96\frac{15}{\sqrt{n}}[/tex]

[tex]3\sqrt{n} = 1.96*15[/tex]

Simplifying both sides by 3

[tex]\sqrt{n} = 1.96*5[/tex]

[tex](\sqrt{n})^2 = (1.96*5)^2[/tex]

[tex]n = 96.04[/tex]

Rounding up(as with a sample size of 96 the margin of error will be slightly above 3):

97 students must be randomly selected for IQ tests.


Related Questions

Each (hypothetical) data set below represents some readings on span gas. Assume the Gauss model, with errors following the normal curve. However, bias may be present. In each case, make a t-test to see whether the instrument is properly calibrated or not. In one case, this is impossible. Which one, and why?

a. 71, 68, 79
b. 71, 68, 79, 84, 78, 85, 69
c. 71
d. 71, 84

Answers

Answer:

71 ( C ).

Step-by-step explanation:

The impossible case is the third case i.e.71

because there is only one reading on the span gas hence it is impossible to carry out a t-test on just one valid reading in an experiment.

BESTIES PLEASE HELP ME

Answers

negative
-6

Not sure about “initial value” possibly either the initial time which is 0, or the initial height which is about 90

What is the LCD for the given equation? 1/v^2=1/3v-2/v^2

Answers

V=9
that’s what I got.

If you know how to solve this, Please answer it. Thank You

The first one to answer the question right, will get Brainlist!

I PROMISE!!!!!​​

Answers

g(x) = 13
f(x) = 25
25{13(5)}= 1625
Answer: 13

Explanation:
f{g[h(x)]}
= f{g[5]}
= f{5 + 8}
= f{13}
= 13^2
= 169

Which ordered pair is NOT a solution to the inequality in the graph? (5,1) (4,6) (0,0) (-2,-8)

Answers

Answer:  (5,1)

====================================================

Explanation:

The red shaded region is the solution set. In other words, if the point is in the red region, then it is a solution. A point like (0,0) is in the red area, so we cross that off the list. The same applies for (4,6) and (-2,-8) as well.

In contrast, a point like (5,1) is not in the red shaded area, so this point is not a solution. Hence it's the final answer.

Note: the solid boundary line means points on the boundary are considered solutions. A dashed boundary line would be used to exclude boundary points from the solution set. Solid boundary lines always go with "or equal to".

Refer to the drawing below if you need a visual of what's going on. I've plotted the four points on the graph given.

--------------------------

Here's an algebraic approach if you don't have a graph and only have the inequality. Ignore this section if you prefer the first section above.

If we plugged (x,y) = (0,0) into the inequality, then we get...

[tex]y \ge 2x-4\\\\0 \ge 2(0)-4\\\\0 \ge 0-4\\\\0 \ge -4\\\\[/tex]

That's a true statement because 0 is to the right of -4 on the number line, making 0 larger than -4. Since the last inequality is true, this makes the first inequality true. Furthermore, it algebraically confirms why (0,0) is a solution. You should find that (4,6) and (-2,-8) will lead to true statements as well, so they are solutions.

In contrast, (x,y) = (5,1) is not a solution because...

[tex]y \ge 2x-4\\\\1 \ge 2(5)-4\\\\1 \ge 10-4\\\\1 \ge 6\\\\[/tex]

which is false. The value 1 is not larger than 6, nor is it equal to 6.

36. Saudi Arabia has proven oil reserves of
2.63 x 1011 barrels. Kuwait has proven oil
reserves of 9.78 x 1010 barrels. Canada
has proven oil reserves of 1.789 x 1011
barrels. What are the combined proven
oil reserves of the three countries?

Answers

Answer:

5.397*10^11

Step-by-step explanation:

2.63*10^11

0.978*10^11

1.789*10^11

--------------

5.397*10^11

The Bransen Family picked 20 red apples, 28 yellow apples, and 12 bushel of green apples. Starting the following day, they ate 2 red apples and 3 yellow apples every day. When 6 red apples are left, how many yellow apples will be left?

Answers

9514 1404 393

Answer:

  7

Step-by-step explanation:

The number of red apples (r) in terms of the number of days (d) is ...

  r = 20 -2d

The number of yellow apples (y) in terms of the number of days (d) is ...

  y = 28 -3d

Using the first equation to write and expression for d, we can substitute into the second equation.

  r -20 = -2d

  (20 -r)/2 = d . . . . from the first equation

Then ...

  y = 28 -3(20 -r)/2 = 28 -30 +3/2r = (3/2)r -2

For 6 red apples left, the number of yellow apples left is ...

  y = (3/2)(6) -2 = 7

7 yellow apples will be left when 6 red apples are left.

Please look at the image

Answers

Answer:

STN = 65 Completing the 180 degrees

115+m(STN)=180

m(STN)=65

mNTR=115

because The NTR and MTS meet theyself

mRTM=65

same The NTR and MTS

because RTM ans STN meet theyself

hopefully you understand it

i am trying hard to explain the question when i solve it but my engilish is not helping to handle it

y is directly proportional to the positive square root of( x+2)² when x = 8 y= 250 find y when x = 4​

Answers

Answer:

150

Step-by-step explanation:

Since y is directly proportional to sqrt((x+2)^2), there is a constant,k, such that

y=ksqrt((x+2)^2)

We are given a pair (x,y) in this relation. Let's plug in (8,250 ) to find k.

250=ksqrt((8+2)^2)

250=ksqrt((10)^2)

250=k10

250/10=k

25=k

So for any pair (x,y) we have the relation y=25((x+2)^2).

We are asked to find y when x=4.

y=25((4+2))^2

y=25(6)

y=150

Test to see if y is proportional to sqrt((x+2)^2)

For the given points: 250/150=10/6

The equation is true so we're great.

Find the circumstance: ?

Answers

The circumference of this circle will be 31.42 cm

1800=3×N
help asap plzzz

Answers

Okay first step is dividing by three on both sides.
1800/3 = 3/3 • N
now you have
600 = N
and you’re done!!! :)

PLEASE HELP WILL GIVE BRAINLIEST

WHAT IS DIVIDED BY 196

Answers

Answer:

1, 2, 4, 7, 14, 28, 49, 98, and 196.

Step-by-step explanation:


[tex]a2 \div a - b + b2 \div b - a[/tex]

Answers

Answer:

0

Step-by-step explanation:

Given

a² ÷ a - b + b² ÷ b - a ← perform the division calculations

= a - b + b - a ← collect like terms

= 0

Answer:

0

Step-by-step explanation:

=a^2/a-b+b^2/b-a

=here denominator which divides a^2 and b^2 gets cancelled

=a-b+b-a

=+a-a and +b -b gets cancelled

and answer is 0

help with this please

Answers

Answer:

( x + 2 ) and ( x - 11 )

Step-by-step explanation:

x² - 9x - 22 = 0

x² + 2x - 11x - 22 = 0

x ( x + 2 ) - 11 ( x + 2 ) = 0

( x + 2 ) ( x - 11 ) = 0

Factors of x² - 9x - 22 are ( x + 2 ) and ( x - 11 ).

Answer:

( x - 11 ) ( x + 2 )

Step-by-step explanation:

x² - 9x - 22 = 0

→ Write 2 factors which multiply to -22 and add to -9

-11 and 2

→ Put the factors into brackets

( x - 11 ) ( x + 2 )

Randomly picking a green care from a standard deck of playing cards

Answers

Okayyyyyyyyyyyyyyyyyyy

3 A random sample of 100 PUJ (public utility jeep) shows that a jeepney is driven on the average 24,500 km per year, with a standard deviation of 3,900 kilometers a Construct a 99% confidence interval for the average number of km a jeepney is driven annually b. What can we assert with 99% confidence about the possible size of our error if we estimate the average number of km driven by jeepney drivers to be 23, 500kn per year

Answers

Answer:

Step-by-step explanation:

M drives past two traffic lights. Probability that both are red is .35 and probability that firest is red is .48. wht is probability that second light is red, given that first light is red?

Answers

Answer:

Step-by-step explanation:

Overall probability = Probability1 *Probability2

Using the data you already have, you can fill it in as

0.35 = 0.48 * P2

Rearrange to isolate P2, by dividing both sides by 0.48, so

0.35/0.48 = P2

P2 = 0.7291666..., which rounded to two d.p is 0.73

So d)0.73 is correct

A building code allows a maximum of 140 people in a meeting room. There is one large table in the room, along with some small tables. When filed, the large table seats 15 people, and the small table each seat 5 people. Which of the following can be used to find t, the greatest number of small tables that can be filled when the large tables are also filled?

Answers

Answer:

25 tables

Step-by-step explanation:

140-15=125

after the big table is filled 125 people are left

small tables fit 5 people

125÷5=25

1 big table and 25 small tables are needed to seat everyone

…..25 tables!!!…






…….hope ……this helps you! …..

help pleaseeeeeeeeeeeeeeeeeeeeeeeee

Answers

Answer:

it is number 2 just read it with an open mind

Step-by-step explanation:

help!!!!!!!!!!!!!!!!!!!

Answers

Answer:

D. 1/5

Step-by-step explanation:

Because

0.2222...>0.2>0.12

The answer is 1/5 hope that helps

Three plants manufacture hard drives and ship them to a warehouse for distribution. Plant I produces 54% of the warehouses inventory with a 4% defect rate. Plant II produces 35% of the warehouses inventory with an 8% defect rate. Plant III produces the remainder of the warehouses inventory with a 12% defect rate. (a) (5 points) A warehouse inspector selects one hard drive at random. What is the probability that a randomly selected hard drive is defectiv

Answers

Answer:

A. 0.028

B. 0.0628

C. 0.45

Step-by-step explanation:

A. Calculation to determine the probability that it is adefective hard drive and from plant II

Using CONDITIONAL PROBABILITY formula

P(B∩A2) =P(A2)P(B|A2)

Let plug in the formula

P(B∩A2)= 0.35×0.08

P(B∩A2)= 0.028

Therefore the probability that it is adefective hard drive and from plant II will be 0.028

B. Calculation to determine the probability that a randomly selected hard drive is defective

Using LAW OF TOTAL PROBABILITY formula

P(B) =P(A1)P(B|A1) +P(A2)P(B|A2) +P(A3)P(B|A3)

Let plug in the formula

P(B)= 0.54×0.04 + 0.35×0.08 + 0.11×0.12

P(B)=0.0216+0.028+0.0132

P(B)= 0.0628

Therefore the probability that a randomly selected hard drive is defective is 0.0628

C. Calculation to determine the probability that it came from plant II

Using CONDITIONAL PROBABILITY formula two twice

P(A2|B) =P(A2∩B)/P(B)

Let plug in the formula

P(A2|B)=0.0280/0.0628

P(A2|B)= 0.45

Therefore the probability that it came from plant II is 0.45

What are the domain and range of the function below? domain: (-40)
range: (-2,00)
domain: (-3,0)
range: [-2.00)
domain: (-0,00
range: -2.00)
domain: [-2.00)
range
CO

Answers

range{-2,00)

Step-by-step explanation:

In the graph the domain is {-3, -1, 0, 1, 2} and range is {-2, 1}

What is a function?

A relation is a function if it has only One y-value for each x-value.

The domain and range are defined for a relation and they are the sets of all the x-coordinates and all the y-coordinates of ordered pairs respectively.

If the relation is, R = {(2, 1), (1, 1), (0, 1), (-1, -2), (-3, -2)}, then:

Domain = the set of all x-coordinates = {-3, -1, 0, 1, 2}

Range = the set of all y-coordinates = {-2, 1}

To learn more on Functions click:

https://brainly.com/question/30721594

#SPJ7

If the function f(x)=Mx+b has an inverse function , which statement must be true

Answers

m≠0, m must not be zero. I hope this helps!

Jose starts with $250 and spends $25 a week. Martin starts with $30 and saves $30 a week. When do Jose and Martin have the
same amount of money? Use for time and for saving.

Answers

Answer:

250-25=225 week 1

200=week 2

175= week 3

150= week 4

Martin

60= week 1

90= week 2

120=week 3

150= week 4

Step-by-step explanation:

A program evaluator wanted to know if a combination of experience and education gave leadership candidates an advantage in meeting job performance standards better than experience alone, or education alone. There were a total of 39 candidates who had both experience and education, and 200 candidates who had either experience or education. Of the candidates who had both experience and education, 21 met the standards, while 18 did not meet the standards. Of the candidates who had only experience or education, 100 met the standards, and 100 did not meet the standards.
Select the correct statistical test to determine if there is a relationship between preparation and meeting the standards, calculate the results, and communicate the results.
a. None of the choices are correct.
b. A Spearman rs is the best choice. The test reveals that there is a strong correlation between preparation and meeting the standards (rs = [237] = 1.00, p <.05). This means there is a relationship between the variables.
c. A chi-square test would be the best choice for examining observed data. The results are significant, (X- [1, N = 239] = 0.19, p<.05). This means that there was a relationship between preparation and meeting the standards, we reject the null hypothesis that the variables are independent.
d. A chi-square test would be the best choice for examining observed data. The results are not significant (X4 [1, N = 239] = 0.19, p > .05). This means that there was not a relationship between preparation and meeting the standards, we retain the null hypothesis that the variables are independent.

Answers

Answer:

pol

Step-by-step explanation:

Question 9
Two sides of a triangle have lengths 10 and 15.
What must be true about the length of the third side?
Greater than 5 but less than 25
Less than 15
Less than 25

Answers

Answer:

Two sides of a triangle have lengths 10 and 15.

What must be true about the length of the third side?

Greater than 5 but less than 25

Less than 15

Less than 25

Step-by-step explanation:

Eugene and Jenny are selling cookie dough for a school fundraiser. Customers can buy packages

of chocolate chip cookie dough and packages of gingerbread cookie dough. Eugene sold i

package of chocolate chip cookie dough and 10 packages of gingerbread cookie dough for a total

of $174. Jenny sold 4 packages of chocolate chip cookie dough and 2 packages of gingerbread

cookie dough for a total of $50. Find the cost each of one package of chocolate chip cookie

dough and one package of gingerbread cookie dough.

.

.

Two sides of a triangle have lengths 10 and 15.

What must be true about the length of the third side?

Greater than 5 but less than 25

Less than 15

Less than 25

.

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at what rate will £420 yield
£70 in 4 years​

Answers

Answer:

4.17%

Step-by-step explanation:

Rate = interest earned / (principal x time)

70 / (4 x 420) = = 0.0417 = 4.17%

After receiving a discount of 14.5% on its bulk order of toner cartridges, John's Office Supply pays $6,498.00. What was the price of the order before the discount?​

Answers

?Answer:

Step-by-step explanation:

26) Cary hiked 18 miles in 6 hours. If he continues at the same pace, how much farther can he hike in the next 2 hours?

27) Harry made 4 hits in 9 times at-bat. If she keeps the same success level, how many hits should she make in 18 times
at-bat?

28) In how many ways can 18 hikers be organized into 2 or more groups for trail clearing if all groups have the same number of hikers?

Mixed Review

Use the rules of divisibility to solve each problem below. Tell whether each number is divisible by 2, 3, 4, 5, 6, 9, or 10.

29) 12

30) 30

31) 360

32) 96

Answers

Answer:

same question

Step-by-step explanation:

A signalized intersection has a cycle length of 70 seconds. For one traffic movement, the displayed all-red time is set to 2 seconds while the displayed yellow time is 5 seconds. The effective red time is 37 seconds and the total lost time per cycle for the movement is 4 seconds. What is the displayed green time for the traffic movement

Answers

Answer:

the displayed green time for the traffic movement is 30 seconds

Step-by-step explanation:

Given the data in the question;

Cycle length; C = 70 seconds

Displayed all-red time; AR = 2 seconds

Displayed yellow time; Y = 5 seconds

Effective red time; r = 37 seconds

total lost time per cycle; [tex]t_L[/tex] = 4 seconds

the displayed green time for the traffic movement; G = ?

First we determine the Effective green time ( g );

Effective red time; r = Cycle length; C - Effective green time ( g )

so,

Effective green time ( g ) = C - r

we substitute

Effective green time ( g ) = 70 seconds - 37 seconds

Effective green time ( g ) = 33 seconds

Now,

Effective green time ( g ) = displayed green time; G + Displayed yellow time; Y + Displayed all-red time; AR - total lost time per cycle; [tex]t_L[/tex]

i.e

g = G + Y + AR - [tex]t_L[/tex]

we substitute

33 = G + 5 + 2 - 4

33 = G + 3

G = 33 - 3

G = 30 seconds

Therefore, the displayed green time for the traffic movement is 30 seconds

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