AP Statistics 4.7 D Calculate the Standard Error and Margin of Error for Estimating the Difference Between Two Population Means Questions

Practise calculating the standard error of a difference between independent sample means by combining the two variance-over-sample-size terms.

Exam points

Compute sqrt(s1 squared/n1 + s2 squared/n2), keeping variances additive for independent samples.

[Maximum number: 1]

A film student was interested in whether there was a difference in the mean file sizes of all movie downloads from a popular streaming service for two genres-comedy and drama. The film student selected a random sample of comedy movies and a random sample of drama movies from the streaming service. The summary statistics are shown in the table.

Table for Question AP Statistics 4.7 D Calculate the Standard Error and Margin of Error for Estimating the Difference Between Two Population Means Questions question 1 — AP Statistics

In a 95 percent confidence interval,which of the following is the standard error of the difference of the two sample means between all comedy movie downloads and all drama movie downloads from the streaming service?

$\sqrt{\frac{113^{2}}{32}+\frac{141^{2}}{41}}$

$\sqrt{\frac{113^{2}}{32}-\frac{141^{2}}{41}}$

$\sqrt{\frac{113^{2}+141^{2}}{32+41}}$

$\sqrt{\frac{113^{2}-141^{2}}{32+41}}$

$\frac{113}{\sqrt{32}}+\frac{141}{\sqrt{41}}$

All question bank results loaded

AP Statistics 4.7 D Calculate the Standard Error and Margin of Error for Estimating the Difference Between Two Population Means Questions question 1