Question 1

1pts

Identify the true statements below regarding the normal distribution.

Group of answer choices

The distribution is symmetrical around the mean.

Theoretically, the mean, median and mode are all equal.

*The distribution is bell shaped.

*The distribution can be fully described by the standard deviation.

Question 2

The normal distribution is very common and therefore you can typically assume normality and calculate the probabilities directly from the data you have collected.

Group of answer choices

*True

False

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Question 3

Given an X value, in order to calculate "upper tail" probabilities with a normal distribution, you need to

Group of answer choices

*Use the inverse function.

Determine first if the value of X is an outlier.

Find the value on the curve associated with X.

Calculate the probability associated with values less than X and subtract this from 1.

Question 4

The entire area under the curve on a normal distribution represents what percentage of the population?

Group of answer choices

100

99.7

68

*95

Question 5

A company that sells annuities must base the annual payout on the probability distribution of the length of life of the participants in the plan.Suppose the lifetimes of the participants is approximately a normal distribution with a mean of 68 years and a standard deviation of 3.5 years.What is the age at which payments have ceased for approximately 90% of the plan participants?

Group of answer choices

There is insufficient information to answer this question.

72.49

*Between 62.24 and 73.76.

65

Question 6

A company that sells annuities must base the annual payout on the probability distribution of the length of life of the participants in the plan.Suppose the lifetimes of the participants is approximately a normal distribution with a mean of 68 years and a standard deviation of 3.5 years. What proportion of the plan recipients die before they reach the standard retirement age of 65?

Group of answer choices

*0.1957

69.35

There is insufficient information to answer this question.

0.8043

Question 7

The following tools can be used to determine if a distribution is normally distributed.Check all that apply.

Group of answer choices

Box Plot

Normal Probability Plot

*Histogram

Anderson-Darling Statistic

*= My answers but I don't know if they're right