Constructing Confidence Intervals

A political pollster wants to know what proportion of voters are planning to vote for the incumbent candidate in an upcoming election. A poll of 150 randomly selected voters is taken from the more than 2,000 voters in the population, and 60% of those selected plan to vote for the incumbent candidate. The pollster wants to use this data to construct a one-sample z interval for a proportion. Which conditions for constructing this confidence interval did their sample meet?

• Random Sample

• Normal

• Independent

Nkechi wants to use a one-sample z interval to estimate what proportion of candies in a bag are red. She takes a random sample of 24 of the 80 total candies and finds that 18 of the candies in the sample are red. Which conditions for constructing this confidence interval did their sample meet?

• Random

• Normal

• Independent

A certain flight transports over 1,000 passengers daily, and the airline is curious what proportion of passengers on this flight don't use overhead bin space. They take an SRS of 40 of these passengers and find that 6 of them don't use overhead bin space. The airline wants to use this data to create a one-sample z interval to estimate the proportion of passengers on this flight don't use overhead bin space. Which conditions for constructing this confidence interval did their sample meet?

Choose all answers that apply:

• Random

• Normal

• Independent

Corey wants to use a one-sample z interval to estimate the proportion of his coworkers who drink coffee every morning. He takes an SRS of 10 of his 50 total coworkers and finds that 6 of those sampled drink coffee every morning. Which conditions for constructing this confidence interval did their sample meet?

Choose all answers that apply:

• Random

• Normal

• Independent

A development expert wants to use a one-sample z interval to estimate the proportion of women aged 16 and over that are literate in Albania. They take an SRS of 50 women from this population and finds that 48 are literate. Which conditions for constructing this confidence interval did their sample meet?

• Random

• Normal

• Independent

A school administrator wants to know what proportion of teachers in their state have a Master's degree. The administrator takes an SRS of 100 teachers from a statewide database containing every teacher, and they find 55 teachers in the sample have a Master's degree. The administrator wants to use this data to construct a one-sample z interval for a proportion. Which conditions for constructing this confidence interval did their sample meet?

• Random

• Normal

• Independent

Ezekiel wants to use a one-sample z interval to estimate the proportion of seniors at his school who have a smartphone. He takes an SRS of 20 of the 100 total seniors and finds that 12 of those sampled have a smartphone. Which conditions for constructing this confidence interval did Ezekiel's sample meet?

• Random

• Normal

• Independent

A certain flight transports over 1,000 passengers daily, and the airline is curious what proportion of passengers on this flight don't use overhead bin space. They take an SRS of 40 of these passengers and find that 30 of them don't use overhead bin space. The airline wants to use this data to create a one-sample z interval to estimate the proportion of passengers on this flight don't use overhead bin space. Which conditions for constructing this confidence interval did the sample meet?

• Random

• Normal

• Independent

Fifteen regions in an Amazon rain forest are randomly sampled. The total yearly rainfalls, in centimeters, for these regions were reported as follows: {181, 232, 230, 158, 242, 197, 228, 302, 242, 194, 200, 186, 146, 194, 202} Assume that yearly rainfalls within the Amazon rain forest are distributed normally. Find a confidence interval for the population mean rainfall in the Amazon rain forest with a 95% confidence level.

x̄ = 35, s = 3.76, n = 25

Find the margin of error for a 90% CI

• 1.34

• 1.29

• 1.19

• 1.22