Chapter 8.1, Problem 20P

For Problems 19–24, please provide the following information.

1. (a) What is the level of significance? State the null and alternate hypotheses. Will you use a left-tailed, right-tailed, or two-tailed test?
2. (b) Check Requirements What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. Compute the z value of the sample test statistic.
3. (c) Find (or estimate) the P-value. Sketch the sampling distribution and show the area corresponding to the P-value.
4. (d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level a?
5. (e) Interpret your conclusion in the context of the application.

20. Glucose Level: Horses Gentle Ben is a Morgan horse at a Colorado dude ranch. Over the past 8 weeks, a veterinarian took the following glucose readings from this horse (in mg/100 ml).

93 88 82 105 99 110 84 89

The sample mean is $\bar{x}$ ≈ 93.8. 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 (Reference: Merck Veterinary Manual). Do these data indicate that Gentle Ben has an overall average glucose level higher than 85? Use α = 0.05.