Question

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

2) On average college students are given homework 3 nights a week. The 95% Confidence Interval is reported as 2 to 6 nights. Answer the following true or false, and correct the “false” statements.  

a.         T    F     The width of a Confidence Interval depends on the sample size.

b.         T    F     You can know for sure that this interval includes the true population

                        parameter.

c.         T    F     This Confidence Interval is interpreted to mean that 95% percent of all 8^th

                        graders in the district are given homework 2 to 6 nights a week.

d.         T    F     The purpose of a Confidence Interval is to provide a range of values which are

                        thought to include the sample mean.

Answer 1

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

since sample size is lage, sample mean follows approximately normal distribution.

Standard error = sd/sqrt(n) = 150/sqrt(1700)

=3.638

The sampling distribution is with mean $3600 and standard deviation of $3.638.

2) On average college students are given homework 3 nights a week. The 95% Confidence Interval is reported as 2 to 6 nights. Answer the following true or false, and correct the “false” statements.  

a.         T    F     The width of a Confidence Interval depends on the sample size.

True

b.         T    F     You can know for sure that this interval includes the true population   parameter.

False. We are 95% confident that this interval includes the true population   parameter.

c.         T    F     This Confidence Interval is interpreted to mean that 95% percent of all 8^th

                        graders in the district are given homework 2 to 6 nights a week.

False. We are 95% confident that this interval ( 2 to 6) includes the true population parameter.

d.         T    F     The purpose of a Confidence Interval is to provide a range of values which are

                        thought to include the sample mean.

False. purpose of a Confidence Interval is to provide a range of values which are thought to include the population mean