Consider a random variable with the following probability distribution:  X          P(X) 0          0.25 1          0.5 2          0.25   What is the standard deviation of X?

You want to test the null hypothesis that the mean amount spent is less than or equal to $1,400 versus a one-tailed alternative. What are the null and alternative hypotheses for this situation?  

The length of a 90% confidence interval for mean Age is which of the following? (Because of potential roundoff, choose the closest.) Data file: Data file – Question 3.xlsx

The file Baseball Players_2015.xlsx, sheet named Baseball Players, contains salary data on all Major League Baseball players for year 2015. Is the average salary for pitcher team Washington Nationals higher than the average for all pitchers?    Note: for datafile, see question 1.

The employee benefits manager of a large public university would like to estimate the proportion of full-time employees who prefer adopting the first (plan A) of three available health care plans in the next annual enrollment period. A random sample of the university’s employees and their tentative health care preferences are given in the file Healthcare.xlsx below. Calculate a 99% confidence interval for the proportion of all the university’s employees who favor plan A. What are the values of lower limit and upper limit? Round your answer to 3 decimal places. Healthcare.xlsx

The file Baseball Players_2015.xlsx, sheet named Baseball Players, contains salary data on all Major League Baseball players for year 2015. What is average salary for the position Pitcher team Washington Nationals? Round your answer to whole number.    Note: for datafile, see question 1.  

Ship collisions in the Houston Ship Channel are rare. Suppose the number of collisions are Poisson distributed, with a mean of 1.4 collisions every four months. What is the probability of having two or less collision over a four-month period? Round you answer to 3 decimal places. For example, if the answer is 0.52443, enter 0.524 below.

The U.S. national average door-to-doctor wait time for patients to see a doctor is now 21.3 minutes. Suppose such wait times are normally distributed with a standard deviation of 6.7 minutes. Some patients will have to wait much shorter than the mean to see the doctor. Based on this information, 20% of patients will have to wait less than how many minutes to see a doctor? Round your answer to one decimal place.

Suppose that two dice are tossed. For each die, it is equally likely that 1, 2, 3, 4, 5, or 6 dots will turn up. Let S be the sum of the two dice. What is the probability that S will be 3 or 11? Round your answer to 3 decimal places.  

The file NBA.xlsx, contains salary data on all National Basketball Association players for year 2018-19. Generate a simple random sample of size 30 from this population. Calculate the population mean of Annual salary. Then calculate the sample mean of Annual salary. What is the sampling error?  How to submit your answer for this question! Answer the questions on the NBA.xlsx file, sheet named NBA. Once completed, upload the Excel file.   Data file: NBA.xlsx