4. According to a 2019 Federal Reserve report, 54% of U.S. young adults who went to college took on some debt for their education. Suppose we take a random sample of 400 U.S. young adults who went to college and took on some debt, a) Find the mean and standard of the sampling distribution of ?̂. mean= ?? = standard deviation of the sample proportion, ?? =   b) Determine the probability that more than 60% of the persons in the sample took on some debt.

The distribution of income in some Third World countries is considered very right skewed (many very poor people, very few middle income people, and even fewer wealthy people). Suppose we pick a country with a severely right skewed distribution. Let the average salary be $2,000 per year with a standard deviation of $8,000. We randomly survey 1,000 residents of that country. a. What is the sampling distribution of the sample mean, including name of the distribution, its mean, error, and standard ?

A. The salaries of pharmacy techs are normally distributed  with a mean of $33,000 and a standard deviation of $4,000.  If a pharmacy tech is selected at random, what is the probability they make more than $38,000?  The answer should be typed as a decimal with 4 decimal places.    B. The salaries of pharmacy techs are normally distributed with a mean of $33,000 and a standard deviation of $4,000. What is the minimum salary to be considered the top 6%?  Round final answer to the nearest whole number.    C. The average number of shoppers at a particular grocery store in one day is 505, and the standard deviation is 115.  The number of shoppers is normally distributed. For a random day, what is the probability that there are between 250 and 450 shoppers at the grocery store?  The answer should be typed as a decimal with 4 decimal places.

Suppose a subdivision on the southwest side of Denver, Colorado, contains 1,800 houses. The subdivision was built in 1983. A sample of 110 houses is selected randomly and evaluated by an appraiser. If the mean appraised value of a house in this subdivision for all houses is $229,000, with a standard deviation of $8,500, what is the probability that the sample average is greater than $231,000? Appendix A Statistical Tables (Round the values of z to 2 decimal places, e.g. 15.25. Round your answer to 4 decimal places, e.g. 0.2513.)enter probability rounded to 4 decimal places

. Each member of a large genetics class grows 12 pea plants from an independent pea family. Each family is expected to have 3/4 plants with smooth peas and 1/4 plants with wrinkled peas. a. On average, how many wrinkled pea plants will a student see in her 12 plants? b. What is the standard deviation of the proportion of wrinkled pea plants per student? c. What is the variance of the proportion of wrinkled pea plants per student? d. Predict what proportion of the students saw exactly two wrinkled pea plants in their sample.

5. The ages of U.S. commercial aircraft have a mean of 13 years and a standard deviation of 7.9 years (based on data from Aviation Data Services). a. If the Federal Aviation Administration randomly selects 35 commercial aircraft for special stress tests, find the probability that the mean age of this sample group is greater than 15 years? b. If the Federal Aviation Administration randomly selects 42 commercial aircraft for special stress tests, what is the mean sample age of the aircraft for the top 75% of the sample?4

2. The average gasoline price of one of the major oil companies has been $1.00 per gallon. Because of shortages in production of crude oil, it is believed that there has been a significant increase in the average price. In order to test this belief, we randomly selected a sample of 36 of the company's gas stations and determined that the average price for the stations in the sample was $1.04. Assume that the standard deviation of the population (o) is $0.12. a) State the null and the alternative hypotheses for testing the belief. b) Describe a Type I error and a Type II error for this situation. c) What is the critical value at a = .05? d) what's your What is the t-statistic or z-statistic associated with the above sample results?

7) $40,000, with a standard deviation of $2000. Assuming that the distribution of income is (approximately) normal, what is the probability that a worker picked at random will have the annual income between $39,000 and $42,000 ? The mean annual income of a worker in a certain professional category is

The distribution of income in some Third World countries is considered very right skewed (many very poor people, very few middle income people, and even fewer wealthy people). Suppose we pick a country with a severely right skewed distribution. Let the average salary be $2,000 per year with a standard deviation of $8,000. We randomly survey 1,000 residents of that country. a. What is the sampling distribution of the sample mean, including name of the distribution, its mean, error, and standard ?

1. Most graduate schools of business require applicants for admission to take the Graduate Management Admission Council's GMAT examination. Scores on the GMAT are roughly normally distributed with a mean of 527 and a standard deviation of 112. a. What is the probability of an individual scoring above 500 on the GMAT? b. How high must an individual score on the GMAT in order to score in the highest 5%? a. 0.5948 a. 0.2348 a. 0.4269 b.x=711.24 b. x=700.21 b. x=721.24