2.  About 13% of the United States population is left-handed…

2.  About 13% of the United States population is left-handed.  Suppose that a researcher speculates that individuals with schizophrenia are more likely to be left-handed than the US population.  The researcher surveys 104 individuals with schizophrenia and finds that 22 of them are left-handed.  Based on this sample, is there enough evidence that the population proportion of individuals with schizophrenia who are left-handed is more than the 13% (or 0.13).  (While answering the following sub-parts of this question, you will be including the null and alternative hypothesis, the test statistic, the p-value (a visualization and an interpretation), your statistical decision, and your conclusion in the context of the problem.) (b) What type of statistical test should be used for this situation?

1.  In 2005-06 the average cost of tuition and fees at priva…

1.  In 2005-06 the average cost of tuition and fees at private four-year colleges was reported at just over $21,000 per year (www.collegeboard.com, October 18th, 2005).  More specifically, the population average cost of tuition and fees for private four-year colleges is $21,325 and the standard deviation is $23,952.  Assume that a random sample of 25 private four-year colleges will be selected. (c)  Will it matter if the distribution of tuition and fee costs in the population is normally distributed?  Why or why not?  (You should be able to answer this in one sentence.)

5. Are men less likely to retire by age 60 than women?  A st…

5. Are men less likely to retire by age 60 than women?  A study was conducted in which 350 men and 350 women were randomly selected to find the proportion of men and women who retired by age 60.  Of the 350 men, 179 retired by age 60.  Of the 350 women, 213 retired by age 60.  The following table displays the data for these two groups. Group n Number who retire by age 60 Males 350 179 Females 350 213 Construct and interpret a 95% confidence interval for the difference in the population proportion of men and women who retire by age 60. (f)  Interpret the 95% confidence interval for the difference in the population proportion of men and women who retire by age 60.

5. Are men less likely to retire by age 60 than women?  A st…

5. Are men less likely to retire by age 60 than women?  A study was conducted in which 350 men and 350 women were randomly selected to find the proportion of men and women who retired by age 60.  Of the 350 men, 179 retired by age 60.  Of the 350 women, 213 retired by age 60.  The following table displays the data for these two groups. Group n Number who retire by age 60 Males 350 179 Females 350 213 Construct and interpret a 95% confidence interval for the difference in the population proportion of men and women who retire by age 60. (c) What is the z-value for the 95% confidence interval?