Question

A.

94

89

80

105

99

112

83

87

The sample mean is x ≈ 93.6. Let x be a random variable representing glucose readings taken from Gentle Ben. We may assume that x has a normal distribution, and we know from past experience that σ = 12.5. The mean glucose level for horses should be μ = 85 mg/100 ml.† Do these data indicate that Gentle Ben has an overall average glucose level higher than 85? Use α = 0.05.

Compute the z value of the sample test statistic. (Round your answer to two decimal places.)

Find (or estimate) the P-value. (Round your answer to four decimal places.)

B.

3.7

2.9

3.8

4.2

4.8

3.1

The sample mean is x = 3.75 grams. Let x be a random variable representing weights of hummingbirds in this part of the Grand Canyon. We assume that x has a normal distribution and σ = 0.84 gram. Suppose it is known that for the population of all Anna's hummingbirds, the mean weight is μ = 4.60 grams. Do the data indicate that the mean weight of these birds in this part of the Grand Canyon is less than 4.60 grams? Use α = 0.10.

Compute the z value of the sample test statistic. (Round your answer to two decimal places.)

Find (or estimate) the P-value. (Round your answer to four decimal places.)

Answer 1

Answer 1

sample mean xbar = 93.6, population mean mu = 85, standard deviation sigma = 12.5 and sample size n = 8

test statistics calculation

Use z value of 1.95 in z distribution table, we get

p-value = 0.0256

Answer 2

sample mean xbar = 3.75, population mean mu = 4.60, standard deviation sigma = 0.84 and sample size n = 6

test statistics calculation

Use z value of -2.48 in z distribution table, we get

p-value = 0.0066