Unformatted text preview: Class Test 3 DATE: Thursday, April-01-10 Instructor: Simin Seury Faculty of Liberal Arts & Professional Studies York University
AP/ECON 2500 3.0: Introductory Statistics for Economists I
Please note: the following only provides a brief guide. Your answer in exam is supposed to
include all steps (formula/calculation etc.) and explanation. Q1. The heights of a simple random sample of 400 male undergraduate in Yorkuca state are
measured. The sample mean is x = 66.2 inches. Suppose that the heights of male
undergraduates follow a Normal distribution with standard deviation σ = 4.1 inches. The
95% confidence interval for µ is:
Ans. (65.80, 66.60) [25 marks] Q2. Fill in the blank with given hints. In a test of statistical hypotheses, the P-value tell us the
smallest level of significance at which the null hypothesis can be rejected
Hints. a) If the null hypothesis is true, b) If the alternative hypothesis is true, c) The largest level
of significance at which the null hypothesis can be rejected, d) The smallest level of significance
at which the null hypothesis can be rejected. [25 marks]
Q3. Explain whether and why each of the following statements is TRUE or FALSE.
a) The margin of error for a 95% confidence interval for the mean µ increases as the sample size
Ans. False [25 marks]
b) The margin of error for a confidence interval for the mean µ, based on a specified sample size
n, increases as the confidence level decreases.
Answer: False [25 marks] ...
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