Is anyone out the statistics? Problem 3
You are a travel agent and want to estimate with a confidence of 95%, the proportion of tourists who intend to travel outside the United States over the next 12 months. Your quotation must be accurate to within 3% of the actual proportion
Find the minimum sample size needed using a previous study which showed that 26% of respondents said they plan to travel outside the United States over the next 12 months.
Problem 4
A light bulb manufacturer claims that the average life of a certain type of bulb is 750 hours.
Application Status mathematically. Give the null and alternative hypotheses. Identify what is the claim
Problem 5
A company that makes cola drinks stipulates that the average content of caffeine per 12 ounce bottle of cola has 40 milligrams. You work as a manager of quality control and are asked to verify this claim. During your test, you find that a random sample of 12-ounce bottles of cola thirty to contain an average of 29.2 milligrams of caffeine with a standard deviation of 7.5 milligrams. At α = 0.01, can you reject the request of the company?
Steps:
a) Write the mathematical claim and identify the null and alternative hypotheses
b) Find the critical values and rejection regions to identify
c) Find the standardized test statistic
d) to decide whether to reject or not reject the null hypothesis
e) interpret the decision in the context of the original application.
Problem 6
An information service on employment claims the average annual earnings for full time workers male over 25 years and had not graduated from high school is 22,300 USD. The annual salary of a random sample of 10 full-time worker men without high school diploma is listed.
At α = 0.05, test of the application that the average salary is $ 22,300.
20,654 21,138 22,355 21,395 22,975
16,912 19,156 23,193 24,180 26,285
Steps:
a) Write the mathematical claim and identify the null and alternative hypotheses
b) Find the critical values and rejection regions to identify
c) Find the standardized test statistic
d) to decide whether to reject or not reject the null hypothesis
e) interpret the decision in the context of the original application.
Problem 7
Claim: p a‰ 0.25, α = 0.05. Sample statistics: = 0.239, n = 105
Decide if the normal sampling distribution can be used. If it can be used, the application test on the p proportion of the population given level of significance α using the statistical sample.
Problem 8
Claim: μ = μ, α = 0.05. Sample statistics: = 16, S1 = 1.1, n1 = 50 = 14, S2 = 1.5, n2 = 50
Steps:
a) Find the test statistic
b) Find the standardized test statistic
c) Decide if the standardized test statistic in the rejection region
d) decide if you should reject or not reject the null hypothesis
The samples are random and independent.
Problem 9
: Îoe> μ, α = 0.05, N1 = 13. N2 = 8
Using Table 5 of Appendix B to find the critical value (s) for the alternative hypothesis above, the significance level α and sample sizes N 1 and N2. Suppose that samples are independent, normal, random and that the population variances are
a) equal b) does not
Problem 10
Claim: μ a‰¥ 0, α = 0.01. Statistics: =- 2.3, s = 1.2, n = 15
Test the claim to mean the difference between two above populations. Use = to test for dependent, random samples given level of importance given to statistics. Is this the criterion of Virginia, left-tailed or two-tailed? Assume that the populations are normally distributed.
go to your book on statistics or graphing calculator and use A to Z - test and not all.
Posted on February 14, 2010.
