Test 10B
AP Statistics
Name:
Directions:
Work on these sheets. Answer completely, but be concise. A normal
probability table is attached.
1. In formulating hypotheses for a statistical test of significance, the null hypothesis is
often
A) a statement that there is “no effect” or “no difference.”
B) the probability of observing the data you actually obtained.
C) a statement that the data are all 0.
D) 0.05.
2. An agricultural researcher plants 25 plots with a new variety of corn. A 90% confidence
interval for the average yield for these plots is found to be 162.72 ± 4.47 bushels per
acre. Which of the following would produce a confidence interval with a smaller margin
of error than this 90% confidence interval?
3. A small company consists of 25 employees. As a service to the employees, the company
arranges for each to have a complete physical for free. Among other things, the weight of
each employee is measured; the mean weight is found to be 165 pounds. The population
standard deviation is 20 pounds. It is believed that a mean weight of 160
pounds would be normal for this group. To see if there is evidence that the mean weight
of the population of all employees of the company differs significantly from 160, the
hypotheses H0:
μ
= 160, Ha:
μ
> 160 are tested. You obtain a Pvalue of less than 0.1056.
Which of the following is true?
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '11
 MR.Smith
 Statistics, Statistical hypothesis testing, researcher

Click to edit the document details