# Descriptive Statistics

Use the given data to find each of the listed values

56 69 64 68 79 56 73 53 62

(a) Mean

(b) Median

(c) Mode

(d) Midrange

(e) P 80

(f) Standard Deviation

(g) Variance

Which is better: A score of 73 on a test with a mean of 75 and a standard deviation of 5 OR a score of 80 on a test with a mean of 85 and a standard deviation of 4.

Find the probability of getting 2 hearts if the cards are drawn from a regular deck and the first card is not replaced

A True/False quiz consist of twenty questions. If a student answers the twenty questions by making random guesses, what is the probability of getting at least one answer correct?

In how many ways can seven books be arranged on a shelf ?

Using the accompanying probability distribution, find the following values:

(a) mean

(b) standard deviation

X P(x)

0 .25

1 .27

2 .05

3 .43

A contest entrant has a .00001 probability of winning $5,000.00. If this is the only prize and the entry fee is $20, then what is the expected value?

Assume that the cure rate for a certain drug is 20% and that 15 patients are tested wth this drug. Find the following:

(a) Mean

(b) Standard Deviation

(c) P (Exactly 4 cures)

(d) P (at least 4 cures)

Assume that IQ scores are normally distributed with a mean of 160 and a standard deviation of 10. An IQ score is randomly selected

(a) Find the probability that the score is above 180

(b) Find the probability that the score is between 130 to 175

A snack company distributes chips in bags labeled 6 ounces. The local Bureau of Weights and Measures randomly selects 50 bags of chips and obtains a sample mean of 5.9 ounces. Assuming that the standard deviation is known to be 0.8, test the claim at the .05 significance level that the bags contain less than 6 ounces.

Identify the following:

(a) Ho

(b) Critical Value

c) Test Statistic

(d) Your conclusion regarding the null hypothesis

(e) Your statement regarding the claim

#### Solution Summary

The solution deals with the calculation of descriptive statistics and probability. Calculation of mean, median, midrange and variance are described in detail with formula and interpretation. The testing procedure for one sample t test is also discussed.