Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Basic stats homework question - where to start?
I can use a TI-83 Plus to answer. Please let me know what feature I should be using and/or how to begin figuring this out (even by hand).
"Suppose the weights of supermodels are normally distributed with a population mean of 120 pounds and a population standard deviation of 5 pounds. A sample of 16 supermodels is randomly chosen and their weights recorded. (No data given. However, use the information given above to determine the answers to the following questions.)
"Imagine the sampling distribution of all possible samples averages of super model weights (with n=16). What is the weight that separates the lightest 25% of sample averages from the heaviest 75% of sample averages? Write the feature of the calculator used as part of your answer."
BeeFree: Thanks for your answer! Based on your profile, I can tell that you know what you're doing. Before I finish up with this question, can you explain why I'm getting an interval instead of just one answer? This questions seems to be asking for a specific value, not a range, so I'm confused as to why it is a confidence interval, or how calculating the 50% interval helps me in this instance.
1 Answer
- BeeFreeLv 79 years agoFavorite Answer
Cara -
This is a 50% Confidence Interval. Why 50%? Because the range will go from 75% down to 25% or a difference of 50%.
TI-83 Instructions:
Choose STAT TESTS , then pick ZInterval and hit enter. For your Input, you want to select Stats.
Now, fill in this information from the problem:
σ = 5
x = 120
n = 16
C-Level = 0.50
Finally, hit Calculate
Answer: 119.16 to 120.84
Hope that helps
