Statistics and Probability Answers

The mean of a normally distributed data is 23.6 with a standard deviation of 4.4. Which of the following scores is considered to be an extreme outlier?

Hypothesis test on population mean; 𝛼 = 0.05; one-tailed test (right); 𝑛 = 37; 𝑠 = 5

The total number of hours, measured in units of 100 hours, that a family runs a vacuum cleaner over a period of one year is a continuous random variable X that has the density function

Find the 90th. Percentile of the t-distribution if the sample size is 25?

Scores of an achievement test show that it follows a normal distribution. Its mean is 79 with a

standard deviation of 8. Find the probability that students’ scores will be higher than the passing score

of 70.

Women’s heights have a mean of 63.6 inches and a standard deviation of 2.5 inches. What is the

probability that a woman will have a height of higher than 70 inches?

possible sample of size 2 which can be drawn without replacement

possible sample of size 2 which can be drawn without replacement

Random samples of size 3 are taken from a population of the numbers 3, 4,5,6, 7,8,and 9.

1. How many samples are possible? List them and compute

the mean of each sample. 2. Construct the sampling distribution of the sample means.

3. Construct the histogram of the sampling distribution of

the sample means. Describe the shape of the histogram.

1. Suppose X is normally distributed with a mean of 5 and a standard deviation of 0.4.Using

  the standard score formula,we findP(X ≤ Xo)=P(Z ≤ 1.3).What is the value of Xo?