Statistics and Probability Answers

Suppose that the mean weight of school children’s bookbags is 17.41 pounds, with a standard deviation of 2.2 pounds. Find the probability that the mean weight of a sample of 30 bookbags will exceed 17 pounds.

Many things closely follow a normal distribution. Give five examples of real-life data which follow this type of pattern. Example: heights of people

9. A garage offers a breakdown recovery service for motorists that is available every day of the

year. According to their records the number of call-outs they received per day last year were:

Number of call-outs: 0 1 2 3 4

Number of days: 68 103 145 37 12

Required: What is the probability that

A. They receive two call-outs in a day?

B. They receive two or fewer call-outs in a day?

C. They receive one or more call-outs in a day?

D. They receive less than four call-outs in a day?

E. They receive more than two call-outs in a day?

A population consists of the four numbers 3 7 11 15 consider all possible sample of size two which can be drawn with replacement

Yna Celestine believes that the average amount of time spent by her classmates

in studying their self learning module in Math per week is less than 300 minutes

with a standard deviation of 45 minutes. She took a random sample of 35 students

in their class and found out that average time spent for studying was 285 minutes.

Test the claim at the 0.05 level of significance.

the mean lifetime of a sample of 100 light tubes produced by a company is found to be 1,580 hours. Test the hypothesis at 5% level of significance that the mean lifetime of the tubes produced by the company is 1,600 hours with standard deviation of 90 hours

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

66

75

53

75

90

79

y

73

56

84

80

71

97

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 value of b? Round your answers to the nearest hundredths.

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

52

70

76

77

77

86

y

74

56

51

74

72

68

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 value of a? Round your answers to the nearest hundredths.

The local coffee shop keeps track of how much coffee they sell versus the temperature on that day, here are their figures:

Sales in Php

1731

1840

1427

1262

1444

1100

Temp in Celsius

21.4

22.9

24.1

26.1

29

31.1

Suppose you want to create a regression equation that will predict the total sales in Php using the temperature of the day in Celcius, what is the value of b? Round your answers to the nearest hundredths.

The local coffee shop keeps track of how much coffee ice cream they sell versus the temperature on that day, here are their figures:

Sales in Php

1690

1786

1391

1555

1111

1423

Temp in Celsius

21.1

24

25.4

26.9

29.6

30.3

Suppose you want to create a regression equation that will predict the total sales in Php using the temperature of the day in Celcius, what is the value of a? Round your answers to the nearest hundredths.