A credit card company claims that the mean credit card debt for individuals is greater than $5,200. You want to test this claim. You find that a random sample of 27 cardholders has a mean credit card balance of $5,435 and a standard deviation of $675. At a = 0.01, can you support the claim? Complete parts (a) through (e) below. Assume the population is normally distributed.

According to a recent survey, the salaries of assistant professors have a mean of $41,750 and a standard deviation of $7000. Assuming that the salaries of assistant professors follow a normal distribution, find the proportion of assistant professors who earn at least $45,000. Round answer to at least 4 decimal places.

Time to Complete Final Exam. The time needed to complete a final examination in a particular college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. Answer the following questions. Assume that 20% of students did not complete the exam. What was the exam duration?

An insurance company is looking over accident statistics. They want to model the population of all drivers for the population parameter of the standard deviation and variance of the age of the driver involved in an automobile accident. They have a sample of 100 accidents from around the country. The age of the driver in each of these accidents is provided below. Use Excel to calculate the sample standard deviation and the sample variance. Round your answers to one decimal place. Do not round until you've calculated your final answer "Age of people in accident"48643346436728189044472440202747683248472248217347302918487364454920205066654187873417203176493089672222455023481746382942254720463119214227226621236675744621461969202048238851284918204522313823284939   Standard deviation:  Variance: