Unit 6 Review - Probs & Stats

What is the purpose of a confidence interval?

• To find the exact proportion of a sample

• To estimate the true population proportion

• To determine the mean of a sample

• To calculate the standard deviation

When should you use a 1-Proportion Z-Interval?

• When you know p

• When the problem involves a quantitative variable

• When you don't know p, but you'd like to

• When the sample size is less than 10

What does a bigger confidence interval indicate about the precision of the estimate?

• More precise

• Less precise

• No change in precision

• Precision is not related to confidence interval

What is the first step in the process for creating a 1-Proportion Z-Interval?

• Define the parameter

• Check conditions to use Normal Model

• Calculate the confidence interval

• Name the interval

Which of the following is NOT a condition to use a Normal Model?

• Independent samples

• Random samples

• Sample size less than 10% of population

• Sample size greater than 50% of population

What is the purpose of a confidence interval?

• To find the true population proportion

• To determine the sample size

• To calculate the mean

• To identify the standard deviation

What is the formula for the standard error in a 1-Proportion Z-Interval?

• SE(𝑝̂) = √(𝑝̂(1−𝑝̂)/𝑛)

• SE(𝑝̂) = 𝑝̂/𝑛

• SE(𝑝̂) = 𝑛/𝑝̂

• SE(𝑝̂) = 𝑝̂(1−𝑝̂)

Which condition must be checked to ensure independent trials in a sample?

• I - Independent trials in sample

• R - Random sample

• T - n ≤ 10% of all M&Ms

• S - np ≥ 10 and n(1-p) ≥ 10

If the claimed proportion p is outside of your confidence interval, what can you conclude?

• There is evidence that the true population proportion is not p.

• There is no evidence that the true population proportion is not p.

• The true population proportion is exactly p.

• The confidence interval is incorrect.

What is the purpose of a 1-Proportion Z-Test?

• To test a claim involving a proportion of a population

• To test a claim involving the mean of a population

• To test a claim involving the variance of a population

• To test a claim involving the standard deviation of a population