can you explain and solve these

A scientist wants to determine whether or not the height of cacti, in feet, in Africa is significantly higher than the height of Mexican cacti. He selects random samples from both regions and obtains the following data. Africa: Mean = 12.1 Sample size = 201 Mexico: Mean = 11.2 Sample size = 238 (a) Which of the following would be the correct hypothesis test procedure to determine if the height of cacti, in feet, in Africa is significantly higher than the height of Mexican cacti? O Two-sample test for proportions O Two-sample t-test O Paired t-test (b) What is the value of the sample statistic to test those hypotheses? (2 decimal places) (c) If the T test statistic is 2.169, and df = 202, find the p-value. (3 decimal places) (d) Select the correct conclusion at alpha = 0.05. O The null hypothesis is rejected. There is insufficient evidence that African cacti are taller on average. O The null hypothesis is rejected. There is sufficient evidence that African cacti are taller on average. O The null hypothesis is not rejected. There is sufficient evidence that African cacti are taller on average. The null hypothesis is not rejected. There is insufficient evidence that African cacti are taller on average.(e) Explain the type of error, in context, that might have been made. 0 Type 11 error, which means the scientist concluded there is a signicant difference between average height of cacti in Africa and cacti in Mexico, when in reality there is no difference. 0 Type 11 error, which means the scientist concluded there is not a signicant difference between average height of cacti in Africa and cacti in Mexico, when in reality there is a difference. 0 Type I error, which means the scientist concluded there is not a significant difference between average height of cacti in Africa and cacti in Mexico, when in reality there is a difference. 0 Type I error, which means the scientist concluded there is a signicant difference between average height of cacti in Africa and cacti in Mexico, when in reality there is no difference. (f) What would the p-vaiue have been if we had done a two-tailed test? (3 decimal places) E As a result of several customer complaints, a furniture company would like to know if its delivery times have increased since the previous year. A random sample of 73 orders from the previous year were examined and their delivery times recorded. Another random sample of 73 orders from the current year were similarly examined. (a) Which type of hypothesis test should be conducted? (b) Which hypotheses should be tested? O Ho: Hcurrent - Mprevious = 0 VS. Ha! "current - Hprevious > 0 O Ho: MD = 0 VS. Ha: MD 0 O Ho: Hcurrent - Mprevious = 0 VS. Ha: Hcurrent - Hprevious * 0 (c) The P-value for was found to be 0.034. For a = 0.05, has the average delivery time increased? O Yes, there is insufficient evidence the average delivery time increased since the previous year. O Yes, there is sufficient evidence the average delivery time has increased since the previous year. O No, there is sufficient evidence the average delivery time increased since the previous year. No, there is insufficient evidence the average delivery time increased since the previous year.Ultrasound is one of many experimental treatments used for soft tissue injuries. In an experiment to gauge the efcacy of this treatment for knee injuries, seven subjects with recent knee injuries were enrolled in a trial. The range of motion (in degrees) of the joint was measured first. After a prescribed ultrasound treatment, the range of motion was measured again. Table 1 below contains the pre and post treatment responses from each of these subjects. Table 1: Knee extensions (degrees) before and after ultrasound Pre 44.4 30.3 50.8 22.9 48.6 60.7 45.8 Post 57.1 55.9 49.4 38.3 55.9 36.8 47.3 Diff || A) In the table above, enter the differences (computed Pre Post) in the empty cells. B) Based on the sample, the average difference in the pre and post treatment responses is :I . (2 decimal places) C) The margin of error for a 98% condence interval for the true average difference in knee extension before versus alter ultrasound treatment is 18.69. Using this margin of error , determine the lower and upper limits for the condence interval. Lower Limit: I: (2 decimal places) Upper Limit: E (2 decimal places) D) Based on the results of this study, at a! = 0.02 we can conclude that There is NOT enough evidence to conclude that ultrasound affects the range of motion Submit Answer ' There is enough evidence to conclude that ultrasound treatment is effective in increasing range 01 motion A study was conducted to compare the proportion of drivers in Boston and New York who wore seat belts while driving. Data were collected, and the proportion wearing seat belts in Boston was 0.581 and the proportion wearing seat belts in New York was 0.832. Due to local laws at the time the study was conducted, it was suspected that a smaller proportion of drivers wear seat belts in Boston than New York. (a) Find the test statistic for this test using Ha: p5