1. Which of the following statements are correct?

a. A normal distributionis any distribution that is not unusual.

b. The graph of a normal distribution is bell-shaped.

c. If a population has a normal distribution, the meanand the medianare not equal.

d. The graph of a normal distribution is symmetric.

Using the 68-95-99.7 rule:

Assume that a set of test scores is normally distributed with a mean of 100 and a standard deviationof 20. Use the 68-95-99.7 rule to find the following quantities:

Suggest you make a drawing and label first

a. Percentage of scores less than 100

b. Relative frequency of scores less than 120

c. Percentage of scores less than 140

d. Percentage of scores less than 80

e. Relative frequency of scores less than 60

f. Percentage of scores greater than 120

2. Assume the body temperatures of healthy adults are normally distributed with a mean of 98.20°F and a standard deviation of 0.62°F (based on datafrom the University of Maryland researchers).

a. If you have a body temperature of 99.00°F, what is your percentilescore?

b. Convert 99.00°F to a standard score (or a z-score).

c. Is a body temperature of 99.00°F unusual? Why or why not?

d. Fifty adults are randomly selected. What is the likelihood that the mean of their body temperatures is 97.98°F or lower?

e. A person’s body temperature is found to be 101.00°F. Is the result unusual? Why or why not? What should you conclude?

f. What body temperature is the 95th percentile?

g. What body temperature is the 5th percentile?

h. Bellevue Hospital in New York City uses 100.6°F as the lowest temperature considered to indicate a fever. What percentage of normal and healthy adults would be considered to have a fever? Does this percentage suggest that a cutoff of 100.6°F is appropriate?

I’m attaching the solution in .doc and .pdf formats.

1. Which of the following statements are correct?

a. A normal distribution is any distribution that is not unusual. False. There are other distributions that are not unusual; for example, uniform distribution, etc.

b. The graph of a normal distribution is bell-shaped. True

c. If a population has a normal distribution, the mean and the median are not equal. False.

The mean and the median of a normal distribution are equal.

d. The graph of a normal distribution is symmetric. True

Statements (b) and (d) are correct.

Using the 68-95-99.7 rule:

Assume that a set of test scores is normally distributed with a mean of 100 and a …

This solution addresses 2 statistics questions, including percentile scores, z scores, normal distribution and relative frequency.