U5D2 Ch.Y.U. - Sampling Proportions & Differences in Sample Proportions
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Last updated 10 months ago
7 questions
According to the American Dental Association, 8% of adults have never had a cavity. A dental graduate student contacts an SRS of 1000 adults and calculates the proportion
in this sample who have never had a cavity.
1
Question 1
1.
Calculate the mean and standard deviation of the sampling distribution of
.
mean = _______
standard deviation = _______
1
Question 2
2.
1
1
At Westville High School there are 315 seniors and 389 juniors. 65% of the seniors have parking passes and 42% of the juniors have parking passes. The statistics teacher selects an SRS of 30 seniors and a separate SRS of 30 juniors.
Let
be the difference in the sample proportions of seniors and juniors that have parking passes.
1
Question 5
5.
What is the shape of the sampling distribution of
? Why?
1
Question 6
6.
1
Is the sampling distribution of
approximately Normal? Show work.
(Check shape)
Question 3
3.
Find the probability that the random sample of 1000 adults will give a result within 2 percentage points of the true proportion.
Question 4
4.
If the sample size were 9000 rather than 1000, how would this change the shape, center, and variability of the sampling distribution of
?
Shape = _______
Center = _______
Variability (S.D.) = _______
Find the mean and standard deviation of the sampling distribution of
Question 7
7.
What is the probability that the difference in sample proportions
(senior – junior) of students with parking passes is greater than 30%?