What is the typical age of a person who renews his or her driver’s license online? From a random sample of 460 driver’s license renewal transactions, the mean age was 42.6 and the standard deviation was 5.4. Compute the 98% confidence interval estimate of the mean age of online renewal users in this county.

Suppose the scores of students on an exam are normally distributed with a mean of 253 and a standard deviation of 80. According to the empirical rule, what percentage of students scored between 13 and 493 on the exam?

Suppose that IQ scores have a bell-shaped distribution with a mean of 103 and a standard deviation of 14. Using the empirical rule, what percentage of IQ scores are at least 145?

In order to be accepted into a certain top university, applicants must score within the top 5% on the SAT exam. Given that the exam has a mean of 1000 and a standard deviation of 200, what is the lowest possible score a student needs to qualify for acceptance into the university?

4. A surgeon is experimenting with a new technique for implanting artificial blood vessels. Using this technique, the mean time for clotting of artificial blood vessel has been 32.5 days with a standard deviation of 2.6 days. How long would a vessel have to stay open to be in the 95th percentile?

York Manufacturing Inc. offers dental insurance to its employees. A recent study by the human resource director shows the annual cost per employee per year followed the normal distribution, with a mean of 1234 dollars and a standard deviation of 321 dollars. What was the minimum cost for the 8 percent of employees that incurred the highest dental expense?

From checking Facebook while walking to class to posting photos on Instagram while eating in the Russell House - social media plays a significant role in the daily lives of college students. The average amount of time a college student spends on social media in the morning (6:00 am - 11:59 am) is normally distributed with a mean of 48 minutes per day and a standard deviation of 12 minutes per day. Suppose on a given morning a college student spends 85 minutes on social-media. Is this unusual?. OA. Not enough information OB. Yes OC. No

The combined math and verbal scores for students taking a national standardized examination for college admission, is normally distributed with a mean of 800 and a standard deviation of 140. If a college requires a minimum score of 900 for admission, what percentage of student do not satisfy that requirement?

A marketing researcher wants to estimate the mean amount spent per year ($) on a web site by membership member shoppers. Suppose a random sample of 100 membership member shoppers who recently made a purchase on the web site yielded a mean amount spent of $55 and a standard deviation of $52. Complete parts (a) and (b) below. a. Is there evidence that the population mean amount spent per year on the web site by membership member shoppers is different from $51? (Use a 0.01 level of significance.) State the null and alternative hypotheses. Ho: H (Type integers or decimals. Do not round. Do not include the $ symbol in your answer.) Identify the critical value(s). The critical value(s) is/are (Type an integer or a decimal. Round to two decimal places as needed. Use a comma to separate answers as needed.) Determine the test statistic. The test statistic, 1STAT, is (Type an integer or a decimal. Round to two decimal places as needed.) State the conclusion. Ho. There is evidence that the…

Many people consider their smart phone to be essential! Communication, news, Internet, entertainment, photos, and just keeping current are all conveniently possible with a smart phone. However, the battery better be charged or the phone is useless. Battery life of course depends on the frequency, duration, and type of use. One study involving heavy use of the phones showed the mean of the battery life to be 11.25 hours with a standard deviation of 3.3 hours. Then the battery needs to be recharged. Assume the battery life between charges is normally distributed. (a) Find the probability that with heavy use, the battery life exceeds 12 hours. (Round your answer to four decimal places.)(b) You are planning your recharging schedule so that the probability your phone will die is no more than 5%. After how many hours should you plan to recharge your phone? (Round your answer to the nearest tenth of an hour.) hours