Solve Statistics Problems due in 3 hours.
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chapter_9_and_11_grp_prob.docxGROUP PROBLEMS - CHAPTERS 9 & 11.1
1. Problem 9.20 Page 375
Determine the null and alternative hypothesis. Classify the test as two tailed, left tail, or right tailed.
2. Problem 9.86 page 397
Show that the assumptions are met and then show the 6 steps of the hypothesis test to complete the problem.
3. Problem 29 p. 435
At the 5% significance level, determine if last year’s mean value lost to purse snatching has decreased from the 2012 mean.
Show that the assumptions are met and then show the 6 steps of the hypothesis test to complete the problem.
4. Problem 11.24 p. 525
Show that the assumptions are met and then show the 6 steps of the hypothesis test to complete the problem.
5. A small electronics store has begun to advertise in the local newspaper. Before advertising, the long term mean weekly sales were $9820. A random sample of 10 weeks while the newspaper ads were running had a sample mean of $10,960 and a sample standard deviation of $1580. From previous data, the distribution of weekly sales is known to be approximately a normal distribution. At the 5% significance, does the data provide sufficient evidence to claim that the population mean weekly sales is now more than $9820.
(a) State the null and alternate hypotheses.
(b) What is the level of significance?
(c) Is this a right-tailed, left-tailed, or two-tailed test?
(d) Show that the assumptions are met for testing this hypothesis
.
(e) Which of the following test procedures is used to test the hypothesis stated in part (a)? NOTE: COMPUTATION OF THE P-VALUE NOT REQUIRED.
a. One mean - Z test
b. One Mean - t test
c. Cannot do test (State why)
(f) If the p-value is 0.0242, is Ho rejected or not?
(g) Write the interpretation of the results of the hypothesis test.
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