Recent survey report claimed that, on average, a person visits doctor at least 5 times per year. A researcher randomly selected 20 people and found that the average of visiting a doctor per year is 3.85, with standard deviation= 2.52. Compute the value of test statistic to justify the claim.

A famous welfare association in Karachi claims that it takes 9 minutes on average to reach its destination in emergency situations. To test this claim, the agency which licences ambulance services had them timed on 50 emergency calls, getting a mean of 10.4 minutes with a standard deviation of 2 minutes. At the 5% significance level test the claim that the average time the ambulance takes to reach its destination is 9 minutes.

The heights of women are normally distributed with a mean of 63.6 inches and a standard deviation of 2.5 inches. (show all work) To be considered extremely tall, a woman’s height must fall in the top 2% for all heights of women. What is the benchmark height for this designation? To be considered extremely short, a woman’s height must fall in the bottom 2% for all heights of women. What is the benchmark height for this designation?

A survey found that​ women's heights are normally distributed with mean 63.3 in. and standard deviation 2.9 in. The survey also found that​ men's heights are normally distributed with mean 69.7 in. and standard deviation 3.6 in. Most of the live characters employed at an amusement park have height requirements of a minimum of 55 in. and a maximum of 64 in.   What's the percentage of men meeting the height requirement. What does the result suggest about the genders of the people who are employed as characters at the amusement​ park?

Experimental components for use in aircraft engines were tested to destruction under extreme conditions. The survival times, in days, of ten components were tested. The mean survival time was determined to be 445.5 days with a standard deviation of 120 days. The experimental components manufactured by the company report that the mean survival time is 430 days. Is there a significant difference between the sample and the claim? Evaluated on a TI 83 calculator

Suppose that IQ scores have a bell-shaped distribution with a mean of 99 and a standard deviation of 17. Using the empirical rule, what percentage of IQ scores are less than 133? Please do not round your answer.

The Fair Isaac Cooperation (FICO) credit score is used by banks and other lenders to determine whether someone is a good credit risk. Scores range from 330 to 850, with a score of 720 or more indicating that a person is a very good credit risk. An economist wants to determine whether the mean FICO score is lower than the cutoff of 720. She finds that a random sample of 60 people had a mean FICO score of 685 with a standard deviation of 80. Can the economist conclude that the mean FICO score is less than 720? Use the a=0.10 level of significance and the P-value method

According to researchers, the mean length of imprisonment for motor-vehicle-theft offenders in a nation is 16.5 months. One hundred randomly selected motor-vehicle-theft offenders in a city in the nation had a mean length of imprisonment of 17.6 months. At the 10% significance level, do the data provide sufficient evidence to conclude that the mean length of imprisonment for motor-vehicle-theft offenders in the city differs from the national mean? Assume that the population standard deviation of the lengths of imprisonment for motor-vehicle-theft offenders in the city is 6.0 months. Click here to view page 1 of the table of areas under the standard normal curve. Click here to view page 2 of the table of areas under the standard normal curve. Ho: H (Type integers or decimals. Do not round.) The test statistic is z = (Round to two decimal places as needed.) Identify the critical value(s). Select the correct choice below and fill in the answer box within your choice. (Round to two decimal…

The Census Bureau reports that 82% of Americans over the age of 25 are high school graduates. A survey of randomly selected residents of certain county included 1130 who were over the age of 25, and 922 of them were high school graduates. (a) Find the mean and standard deviation for the number of high school graduates in groups of 1130 Americans over the age of 25. Mean = 926.6 Standard deviation = 12.9933

After sitting in the waiting room for 12 minutes, a patient begins to complain. Is this patient’s wait time unusual?