Calculating One-Sample T Intervals for Means

The video tutorial explains how a nutritionist estimates the average caloric content of burritos at a restaurant by taking a random sample of 14 burritos. It covers calculating the sample mean and standard deviation, and constructing a 95% confidence interval using a t-statistic due to unknown population standard deviation. The tutorial also discusses the importance of degrees of freedom and critical values in determining the confidence interval. Finally, it validates the confidence interval by checking conditions like random sampling, normal distribution, and independence.

What was the average caloric content of the burrito sample?

• 700 calories

• 750 calories

• 650 calories

• 600 calories

How many burritos were sampled in this study?

• 10

• 12

• 14

• 16

What was the standard deviation of the burrito sample?

• 70 calories

• 50 calories

• 60 calories

• 40 calories

Why was a t-statistic used in the calculation of the confidence interval?

• Population mean was known

• Sample size was large

• Sample was not random

• Population standard deviation was unknown

What is the degrees of freedom used in this study?

• 12

• 15

• 13

• 14

What critical value is used for the 95% confidence interval from the t-table?

• 1.96

• 1.645

• 2.16

• 2.58

What is the calculated margin of error for the confidence interval?

• 30

• 35

• 28.9

• 25

What condition validates the use of the normal distribution in this study?

• Sample size over 30

• Sample is random

• Sample data is symmetric

• All of the above

What percentage of the burrito population must the sample represent to meet the independence condition?

• More than 10%

• Less than 5%

• Less than 10%

• Exactly 10%

Which of the following is a requirement for constructing a valid confidence interval?

• Random sampling

• Known population mean

• Large population standard deviation

• Non-symmetric data