Many students face the problems when they start studying the Statistics and Probability subject. Trying to understand a lot of different aspects they feel stressed and that doesn’t have a beneficial effect on their health. Students have a great deal of statistics and probability questions that they puzzle over every day. Our service will provide every client with the statistics and probability answers. We promise to do our best to help you solve your statistics and probability problems, just let us know your problem and you will get the best statistics and probability answers ever!
Economists frequently make use of quintiles (i.e., the 20th, 40th, 60th, and 80th percentiles) particularly
when discussing incomes. Suppose that in a large city household incomes are normally distributed
with a mean of $50,000 and a standard deviation of $10,000. An economist wishes to identify the
quintiles. Unfortunately, he did not pass his statistics course. Help him by providing the quintiles.
How much money does a typical family of four spend at a McDonald’s restaurant per visit? The amount is a normally distributed random variable with a mean of $16.40 and a standard deviation of $2.75.
a. Find the probability that a family of four spends less than $10.
b. What is the amount below which only 10% of families of four spend at McDonald’s?
Sugar is packed in 5-pound bags. An inspector suspects the bags may not contain 5 pounds. A sample of 50 bags produces a mean of 4.6 pounds and a standard deviation of 0.7 pound. Is there enough evidence to conclude that the bags do not contain 5 pounds as stated, at α = 0.05? Also, find the 95% confidence interval of the true mean.