Statistics and Probability Answers

reading test is given to an elementary school class that consists of 12 Anglo

-

American children and 10 Mexico

-American children. The results of test are :

Anglo American Mexico American

Mean 74 70

Std.

8 10

Is the difference between means of the two groups significantly at the 0.05 level of

significance? Value of

t at 5% level for 20 degree is freedom is 2.086

.

4. The following are the list of enrollments for the colleges that offer bachelor's degree in different field of studies

1750, 1069, 1723, 1827, 1155, 1714, 2391, 2155, 1412, 1688 2471, 1759, 3008, 2511, 2577, 1082, 1067, 1062, 1319, 1037, 2400.

1013, 1867, 1268, 1666, 2309, 1231, 3005, 28 , 2166, 1136, 1532, 1461,

Required: Using the given information you are request to compute the following:

A. Construct a grouped frequency distribution with the six classes.

B. Identify the modal class and calculate the mean for the distribution.

C. Determine the modal class and calculate the mean for the distribution.

5. Given the following data, (A) Find the median, quartiles and semi-interquartile range, (B) Find the 8 ^ (th) deciles and 85 ^ (th) percentiles.

1976, 2162, 1502, 1782, 1523, 2033 1564, 20, 19 , 1714, 1841 1648, 1 1345, 1837, 1718, 2047, 1954, 2000, 1479, 2571, 1739, 1781

6. Two neighbors work at the same place. One travels to work by bus, the other cycles to work. The times taken (in minutes) by each transport to get to work on a sample of 8 days were given as follows:

Bus-33, 28, 40, 32, 41, 32, 38, 42

Cyclist-26, 33, 27, 31, 31, 30, 28, 24

Required: Calculate the mean and standard deviation for each set of times and use them to compare the travel times for the two commuters.

7. An electrical goods retailer sold video recorders to 8200 customers last year and extended warranties to 3500 of these customers. When the retailer sells a video recorder, what is the probability that:

A. The customer will buy an extended warranty?

B. The customer will not buy an extended warranty?

Let x be a random variable that represents the percentage of successful free throws a professional basketball player makes in a season. Let y be a random variable that represents the percentage of successful field goals a professional basketball player makes in a season.

The table below shows the percentage of successful free throws and field goals a professional basketball player makes in a season:

x

72

79

56

81

82

98

y

71

66

60

68

61

94

Suppose you want to predict the percentage of successful field goals a professional basketball player using the percentage of successful free throws, what is the percentage of successful field goals if the percentage of successful free throws is 49? Round your answers to the nearest hundredths.