Statistics and Probability Answers

The amount of coffee dispensed by a vending machine is assumed to be normally distributed, A vendor claims that the mean amount of coffer dispensed by the machine is 6 ounces per cup. The office manager doubted this claim. He randomly selected 25 cups of coffee from this machine and recorded the amount of coffee dispensed in each. The sample mean is 5.8 ounces with a standard deviation of 0.8 ounces, do the data provide sufficient evidence to indicate that the mean amount of coffee dispensed is not equal to 6 ounces per cup use 0.05 level of significance.

2. A sample of 40 sales receipts from a grocery store has sample mean of 137 and population sd= 30.2. Use these values to test whether or not the mean sales the grocery store is less than 150. Use a 95% confidence level

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days. About what percent of the products last between 9 and 12 days?

Find the range, variance, and standard deviation unless the question asks for something different.

Police Calls in Schools. The number of incidents in which police were needed for a sample of 10

schools in Allegheny County is 7, 37, 3, 8, 48, 11, 6, 0, 10, 3. Are the data consistent or do they

vary? Explain your answer

Find the range, variance, and standard deviation unless the question asks for something different.

Passenger Vehicle Deaths. The number of people killed in each state from passenger vehicle

crashes for a specific year is shown

778 309 1110 324 705

1067 826 76 205 152

218 492 65 186 712

193 262 452 875 82

730 1185 2707 1279 390

305 123 948 343 602

69 451 951 104 985

155 450 2080 565 875

414 981 2786 82 793

214 130 396 620 797

Find (a) the mean, (b) the median, (c) the mode, and (d) the midrange.

Observers in the Frogwatch Program. The number of observers in the Frogwatch USA

program (a wildlife conservation program dedicated to helping conserve frogs and toads) for the

top 10 states with the most observers is 484, 483, 422, 396, 378, 352, 338, 331, 318, and 302. The

top 10 states with the most active watchers list these numbers of visits: 634, 464, 406, 267, 219,

194, 191, 150, 130, and 114. Compare the measures of central tendency for these two groups of

data

A. Find (a) the mean, (b) the median, (c) the mode, and (d) the midrange.

High Temperatures. The reported high temperatures (in degrees Fahrenheit) for selected world

cities on an October day are shown below. Which measure of central tendency do you think best

describes these data?

62 42

76 38

66 91

79 66

83 77

61 90

62 74

85 63

72 64

64 68

74 42

71

Find (a) the mean, (b) the median, (c) the mode, and (d) the midrange.

Grade Point Averages. The average undergraduate grade point average (GPA) for the 25

top-ranked medical schools is listed below

3.80 3.77 3.70 3.74 3.70

3.86 3.76 3.68 3.67 3.57

3.83 3.70 3.80 3.74 3.67

3.78 3.74 3.73 3.65 3.66

3.75 3.64 3.78 3.73 3.64

Suppose the mean amount of cholesterol in eggs labeled “large” is 186 milligrams, with a standard deviation of 7 milligrams. Find the probability that the mean amount of cholesterol in a sample of 144 eggs will be within 2 milligrams of the population mean.