The candy machine Suppose a large candy machine has 15%orange candies. Imagine taking an localid="1652783380833" SRSof localid="1652783389017" 25candies from the machine and observing the sample proportion localid="1652783396603" p^of orange candies.

(a) What is the mean of the sampling distribution of localid="1652783403494" p^? Why?

(b) Find the standard deviation of the sampling distribution of localid="1652783417404" p^. Check to see if the localid="1652783410131" 10%condition is met.

(c) Is the sampling distribution of localid="1652783430137" p^approximately Normal? Check to see if the Normal condition is met.

(d) If the sample size were localid="1652783436404" 75rather than localid="1652783443101" 25, how would this change the sampling distribution of localid="1652783450320" p^

Short Answer

Expert verified

a). The required mean is 0.15.

b). The required standard deviation is localid="1652784804305" 0.0714143.

c). localid="1652784834600" p^sample distribution is not close to Normal.

d). The standard deviation islocalid="1652784839897" 0.57445.

Step by step solution

01

Part (a) Step 1: Given Information

Given in the question that, a large candy machine has15percent of orange candies

SRS=25candy count.

02

Part (a) Step 2: Explanation

Assume that the sample size for SRS is nand that the sample distribution is p.

So, n=25and

p=15%

=0.15

The mean of a sample proportion's sampling distribution p^and the population proportion pare the same, i.e., μp^=p.

In the given formula, replace pwith 0.15.

μp^=0.15

The mean is μp^=0.15since the sampling proportion is an unbiased estimate for the population proportion.

03

Part (b) Step 1: Given Information

15percent of orange candies in the machine.

SRS =25candy count.

04

Part (b) Step 2: Explanation

Assume the sample distribution is pand the sample size is n.

p=15%

=0.15

And, n=25

Determine the standard deviation of the sampling distribution:

p^is σp^=p(1-p)n

Substitute 0.15for pand 25for n:

σp^=0.15(1-0.15)25

=0.15×0.8525

=0.0051

0.0714143

05

Part (c) Step 1: Given Information

15percent of orange candies in the machine.

SRS 25candy count.

06

Part (c) Step 2: Explanation

Assume that the sample distribution be pand sample size for SRS be n.

p=15%

And, n=25

The product of sample size and the sampling proportion that is, npand n(1-p)both are less than at least 10then the distribution of the samples is roughly Normal.

In the expression np, substitute 0.15for pand 25for n.

25×(0.15)=3.75

07

Part (c) Step 3: Explanation

In the expression n(1-p), substitute 0.15for pand 25for n.

25(1-0.15)=25×0.85

=21.75

Both npand n(1-p)are fewer than 10, indicating that the Normal distribution requirement has not been satisfied.

As a result, p^'s sampling distribution is not close to Normal.

08

Part (d) Step 1: Given Information

15percent of orange candies in the machine.

SRS 25candy count.

09

Part (d) Step 2: Explanation

Assume the sample distribution is pand the SRS sample size isn.

p=15

And,

n=75

Know that the standard deviation of the sampling distribution of p^is σp^=p(1-p)n.

Simplify the preceding equation by substituting 0.15for pand 75for n.

σp^=0.15(1-0.15)75

=0.45×0.5575

=0.0033

0.057445

Therefore, the standard deviation is 0.057445.

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