Statistics Questions
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A 95% confidence interval for the average salary of all CEOs in the electronics industry was constructed using the results of a random survey of 45 CEOs. The interval was ($97,911, $110,014). To make more useful inferences from the data, it is desired to reduce the width of the confidence interval. Which of the following will result in a reduced interval width?
The critical value of a distribution is the value of
It is desired to estimate to estimate the average total compensation of CEOs in the service industry. Data were randomly collected from 18 CEOs and the 97% confidence interval was calculated to be ($2,181,260, $5,836,180). Based on the interval above, do you believe the average total compensation of CEOs in the service industry is more than $3,000,000?
A marketing research company is estimating the average total compensation of CEOs in the service industry. Data were randomly collected from 18 CEOs and the 97% confidence interval for the mean was calculated to be ($2,181,260, $5,836,180). What would happen tp the confidence interval if the confidence level were changed to 95%?
True or False: A confidence interval with a 95% level of confidence means that the parameter will be in the interval for 95 out of 100 samples of the sample size.
True or False: Other things bing equal, the confidence interval for the mean will be wider for 95% confidence than for 90% confidence.
The normal density curve is symmetric about
The power of a statistical test is the probability of
Sally's z-score on a given measure is -2.5, where the population mean is 5 and the standard deviation is 1.5. What is Sally's raw score?
Chris wants to calculate a z-score for his own height. The average height in the class is 66 inches, and Chris's height is 62 inches. Chris calculated his z-score to be +1.5. What's wrong with his calculation?
The mean GPA of the students in the sample is 2.98. According to the school registrar, the mean GPA of all 2544 students at McNeil is 3.09. Which number represents the statistic?
A study about the college aptitude of seniors at North City High School has resulted in a sample mean with a corresponding z-score of −2.00. If the critical value for the region of rejection is ± 1.96 what is the correct conclusion?
You are planning to purchase food for your club's concession stand during a football game and would like to know what type of food to buy and how much. What is your population of interest?a. All high school studentsb. Spectators at the football gamec. The football team
A research group wishes to know the mean GPA of all 2544 students at McNeil High School. To estimate this, they take a random sample of 189 students from all 1st period classes in the A wing, and record their current GPA. What is the population of interest?
You are contacting five state governments around the US to compile data to compare the different states. What is the population?
Are stratified and cluster samples different?
Multistage sampling:Nielsen randomly selects households and monitors the television programs these households are watching through a People Meter. The meter is an electronic box placed on each TV within the household. The People Meter measures what program is being watched and who is watching it. Nielsen selects the households with the use of a two-stage sampling process.What is the 1st stage?
In research, we wish to determine how varying the amount of an _____ variable affects the value of a _____ variable
Illustrating simple random sampling: suppose a study group of consists of 5 students-Bob, Patricia, Mike, Jan, and Maria2 of the students must go to the board to demonstrate a homework problem. List all possible samples of size 2 (without replacement).
In a study: the goal of the research was to determine if radio frequencies from cell phones increase the risk of contracting brain tumors. What is the response variable?