Reference no: EM132465061
The national mean (u) absentee rate of workers working for the Old Mill Store Company is reported as. 8,25 days per year. The mean rate (Xbar) for a sample of 14 workers at your old mill store franchise is 7.53 days per year with a standard deviation (s) of 2.72 days.
a. State an appropriate null hypothesis
b. What is the value of the calculated test statistic (t)?
c. Identify the critical value. (setting the level of significance at .05)
d. State your conclusion.
A recent news report asserts that the weekly mean number (μ) of drinks (both mixed drinks and beer) consumed by college students is 12.56 drinks. Data from a sample of 30 students enrolled at your university indicate a weekly consumption level (Xbar) of 11.21 drinks, with a standard deviation (s) of 3.88. Assume that you're working at the .05 level of significance.
a. State an appropriate null hypothesis
b. What is the value of the calculated test statistic (t)?
c. Identify the critical value.
d. State your conclusion.
Graduating seniors in high schools have an average (u) reading comprehension score of 72.55 with a standard deviation (o) of 12.62. An instructor in a GED program wants to compare his students with other students. Selecting a random sample of 70 student, the same reading comprehensive test results show a sample mean (x) of 79.53. Assume that he set .05 level of significance
a. State an appropriate null hypothesis
b. What is the value of the calculated test statistic (Z)?
c. State your conclusion
Assume that you are working with the results of a research based on 25 participants. The mean difference (Dbar) is 9.72, with an estimate of the standard error of the mean difference sDbar = 6.33. Set your level of significance at .05.
Formulate an appropriate null hypothesis and calculate t.
Identify the critical value and state your conclusion.
2. Consider a research project involving two independent samples: Sample A and Sample B:
Mean of Sample A = 30.45, n = 25
Mean of Sample B = 26.54, n =27
Estimate of the standard error of the difference of means sxbar1-xbar2 = 2.15. Set your level of significance at .05.
Formulate an appropriate null hypothesis and calculate t statistic.
Identify the critical value and state your conclusion.