Question

1) μ: $3600 per student    σ: $150 Distribution: Skewed to the left

a.       Draw a well-labeled picture of the relevant sampling distribution for this population data including its standardization (z), assuming the sample size is 1700 school districts.

b. Number of cases in sampling distribution is ?

c.       What would it mean to have a frequency of 400 for the value $1700 in this sampling distribution?  

d.       Standard error?

2) 185 female who answered the question about race and friendship, 45% reported having friends of a different race is “desirable”. However, of the 867 male who answered the question about race and friendship, only 39% reported that having friends of a different race is “desirable". 95% Confidence Interval (CI) for all proportion ?? write a brief summary.

Answer 1

a)

The sampling distribution of sample mean has sample mean is:

The standard deviation

b)

Number of cases in sampling distribution is: Number of samples of size 1700 taken

c)

The freqeuncy of 400 means from all the samples 400 samples have mean $1700.

d)

The standard error is:

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2)

For 95% confidence interval, using excel function "=NORMSINV(0.975)", critical value of z will be

For female:

Here we have

Confidence interval for population proportion will be

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For male:

Here we have

Confidence interval for population proportion will be