1.

For students who rst enrolled in two-year public institutions in a recent semester, the proportion who earned a bachelor's degree within six years was 0.388. The president of a certain junior college believes that the proportion of students who enroll in her institution have a higher completion rate. (a) State the null and alternative hypotheses in words. (b) State the null and alternative hypotheses symbolically. (1:) Explain what it would mean to make a Type I error. (d) Explain what it would mean to make a Type II error. Three years ago, the mean price of an existing single-family home was $243,715. A real estate broker believes that existing home prices in her neighborhood are higher. (a) State the null and alternative hypotheses in words. (b) State the null and alternative hypotheses symbolically. (c) Explain what it would mean to make a Type I error. (d) Explain what it would mean to make a Type II error. The standard deviation in the pressure required to open a certain valve is known to be a = 0.5 psi. Due to changes in the manufacturing process, the quality-control manager feels that the pressure variability has increased. (a) State the null and alternative hypotheses in words. (b) State the null and alternative hypotheses symbolically. (6) Explain what it would mean to make a Type I error. (d) Explain what it would mean to make a Type II error. According to a report, the standard deviation of monthly cell phone bills was $4.89 in 2017. Aresearcher suspects that the standard deviation of monthly cell phone bills is different today. (a) State the null and alternative hypotheses in words. (b) State the null and alternative hypotheses symbolically. (c) Explain what it would mean to make a Type I error. (d) Explain what it would mean to make a Type II error. Test the hypothesis using the P-value approach. Be sure to verify the requirements of the test. H0: p = 0.6 versus H1: p > 0.6 n =200; X: 125; or = 0.01 Click here to view [age 1 of the table. Click here to View [age 2 of the table. Calculate the test statistic, zo. ZO=D (Round to two decimal places as needed.) Test the hypothesis using the P-value approach. Be sure to verify the requirements of the test. H0: p = 0.6 versus H1: p > 0.6 n =250; X: 160, on = 0.05