You want to obtain a sample to estimate how much parents spend on their kids birthday parties. Based on previous study, you believe the population standard deviation is approximately σ=22.7σ=22.7 dollars. You would like to be 99% confident that your estimate is within 2 dollar(s) of average spending on the birthday parties. How many parents do you have to sample?

On an exam with a M =78, you obtain a score of X = 84. Would you prefer a standard deviation of S = 2 or S =10? Explain your answer.   Using the above numbers, calculate the population mean. If 5 points were added to every score in the population, what would be the new mean and standard deviation. If every score was multiplied by five, what would be the new standard deviation?

Scores on the Wechsler Adult Intelligence Scale for the 2020 to 3434 age group are approximately Normally distributed with a mean of 110 and a standard deviation of 15. How high must a person score to be in the top 5%5% of all scores? Enter your answer as a whole number.

A survey collected the data below. x 26 4 16 12 20 The mean is 15.6. Calculate the deviation of x=16 ?

A successful basketball player has a height of 6 feet 11 ​inches, or 211 cm. Based on statistics from a data​ set, his height converts to the z score of 5.17. How many standard deviations is his height above the​ mean?

A population has a mean μ = 70 and a standard deviation o=36. Find the mean and standard deviation of a sampling distribution of sample means with sample size n = 81. H=(Simplify your answer.) = (Simplify your answer.)

You have a normal population with a mean of 1000 and a standard deviation of 100.Determine the scores associated with the following percentiles:   50% 45% 95% 5% 77%

In an Algebra class, the scores on a test are normally distributed. The middle 68% of the scores fall between 69 and 81. What are the mean and standard deviation for this data? Standard Normal Curve Mean: Standard Deviation:

A normal population has mean u = 50 and standard deviation o = 5. What is the 80th percentile of the population? Use the TI-84 Plus calculator. Round the answer to at least one decimal place.