StatProb Lesson 4 Quiz Reviewer (SY 23 - 24)

A random sample of 10 students yielded the following grades in math:

90, 93, 85, 77, 88, 80, 78, 83, 95, 90

Assume that the population of math grades is normally distributed. What is a point estimate for the population mean? Do not round off your answer.

In a local survey, 546 of the 684 respondents indicated support for a ban on household aerosols. In solving for a point estimate for the population proportion, which value is x, which is the number of successes in the sample?

In a local survey, 546 of the 684 respondents indicated support for a ban on household aerosols. What is the proportion of successes? (3 d. p.)

In a local survey, 546 of the 684 respondents indicated support for a ban on household aerosols. What is the margin of error for a 95% confidence interval? (3 d. p.)

In a local survey, 546 of the 684 respondents indicated support for a ban on household aerosols. Interpret the results of the 95% confidence interval for the population proportion of people who support the ban.

• With 95% confidence, we can say that the population proportion of people who support the ban on household aerosols is between 76.8% and 82.8%

• With 95% confidence, we can say that the population proportion of people who support the ban on household aerosols is between 77.3% and 82.3%

• With 95% confidence, we can say that the population proportion of people who support the ban on household aerosols is between 74.8% and 83.8%

• With 95% confidence, we can say that the population proportion of people who support the ban on household aerosols is between 76.4% and 83.2%

Does the following situation involve a normal distribution, a t-distribution, or neither? A telecommunications company wants to estimate the mean length of time (in minutes) that 18- to 24-year olds spend browsing their social media accounts each day. In a random sample of thirty-one 18- to 24-year olds, the mean length of time spent browsing their social media accounts was 29 minutes and the standard deviation was 4.5 minutes.

• normal distribution

• t-distribution

• neither

A telecommunications company wants to estimate the mean length of time (in minutes) that 18- to 24-year olds spend browsing their social media accounts each day. In a random sample of thirty-one 18- to 24-year olds, the mean length of time spent browsing their social media accounts was 29 minutes and the standard deviation was 4.5 minutes. What is the margin of error for a 90% confidence interval? (1 d. p.)

A telecommunications company wants to estimate the mean length of time (in minutes) that 18- to 24-year olds spend browsing their social media accounts each day. In a random sample of thirty-one 18- to 24-year olds, the mean length of time spent browsing their social media accounts was 29 minutes and the standard deviation was 4.5 minutes. What is a 90% confidence interval for the population mean length of time? (1 d. p.)

• 71

• 50

• 8

• 29

• 271

• 385

• 664

• 409