The mean monthly salary of a random sample of 20 college graduates under the age of 30 was found to be $ 3120 with a standard deviation of $677.Assume that the distribution of salaries for all college graduates under the age of 30 is normally distributed.

7. Construct a 90% confidence interval for  , the population mean of monthly salaries of all college graduates under the age of 30.

a) (1408, 4831) b) (1058, 1582) c) (1071, 1569) d) (2858, 3381) e) (2741, 3498)

8. all other information remaining unchanged, which of the following would produce a wider interval than the 90% confidence interval construct above?

a)A sample of size 28 instead of 20 b) A sample of size 24 instead of 20 c) An 80% confidence interval rather than a 90% confidence interval d) A sample with a standard deviation of 525 instead of 677 e) A sample with a standard deviation of 725 instead of 677

More tips

• C Computers and Internet How to Properly Order Clothing from International Online Stores...
• F Food and Cooking How to Calculate the Gender of Your Child with Blood?...
• S Society and Politics 10 Tips for Boosting Your Self-Esteem...
• C Computers and Internet How to Create a Folder on Your iPhone?...
• G Goods and services How to sew a ribbon: Tips for beginners...
• F Food and Cooking How to Make Mayonnaise at Home? Secrets of Homemade Mayonnaise...
• C Computers and Internet Which Phone is Best for Internet Surfing?...
• F Food and Cooking Everything You Need to Know About Pasta...
• C Computers and Internet How to Choose a Monitor?...
• H Horoscopes, Magic, Divination Where Did Tarot Cards Come From?...

Answers on questions: Mathematics