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A cereal company claims that its cereal boxes contain an average of of cereal. A consumer group tests a random sample and constructs a confidence interval for the true mean weight:
You are given the following null hypothesis:
Does the confidence interval suggest that you should reject ? Explain your reasoning.
A beverage company claims that the average sugar content in its soft drinks is grams per bottle. A nutrition researcher collects a random sample and constructs a confidence interval for the mean sugar content: ( grams, grams)
You are given the following null hypothesis: grams
Does the confidence interval suggest that you should reject ? Explain your reasoning.
A battery company claims that its new phone battery lasts at least hours on average. A testing lab gathers a sample of batteries and constructs a confidence interval for the true average battery life:
( hours, hours)
You are given the following null hypothesis:
hours
Does the confidence interval suggest that you should reject ? Explain your reasoning.
A fitness program is evaluated by measuring the number of push-ups completed by participants before and after a -week training. The results are:
Construct the confidence interval for the mean difference in push-up counts. What does the interval suggest about the program's effectiveness?
A researcher wants to investigate whether there is a significant difference in the resting heart rates in beats per minute of individuals before and after a -week exercise program. The paired data below represent the heart rates of participants before and after the program.
Construct a percent confidence interval for the mean difference in heart rates Before minus After. What does it suggest about the effect of the exercise program?