Men On Mars? Do you feel that the US should seek after a program to send people to Mars? An assessment of public sentiment led by the Related Press showed that 49% of the 1034 grown-ups reviewed feel that we should seek after such a program.5
a. Gauge the genuine extent of Americans who imagine that the US should seek after a program to send people to Mars. Figure the room for mistakes. b. The inquiry presented to some extent a was just one of numerous inquiries concerning our space program that were asked in the assessment of public sentiment. In the event that the Related Press needed to report one inspecting blunder that would be legitimate for the whole survey, what worth would it be a good idea for them to report?
Cure for the Common Cold? An experiment was planned to compare the mean time (in days) required to recover from a common cold for persons given a daily dose of 4 milligrams (mg) of vitamin C versus those who were not given a vitamin supplement. Suppose that 35 adults were randomly selected for each treatment category and that the mean recovery times and standard deviations for the two groups were as follows: No Vitamin 4 mg Supplement Vitamin C Sample Size 35 35 Sample Mean 6.9 5.8 Sample Standard Deviation 2.9 1.2 a. If your research objective is to show that the use of vitamin C reduces the mean time required to recover from a common cold and its complications, give the null and alternative hypotheses for the test. Is this a one- or a two-tailed test? b. Conduct the statistical test of the null hypothesis in part a and state your conclusion. Test using a = .05.Lead Levels in Drinking Water Analyses of drinking water samples for 100 homes in each of two different sections of a city gave the following means and standard deviations of lead levels (in parts per million): Section 1 Section 2 Sample Size 100 100 Mean 34.1 36.0 Standard Deviation 5.9 6.0 a. Calculate the test statistic and its p-value to test for a difference in the two population means. Use the p-value to evaluate the statistical significance of the results at the 5% level. b. Use a 95% confidence interval to estimate the difference in the mean lead levels for the two sections of the city. c. Suppose that the city environmental engineers will be concerned only if they detect a difference of more than 5 parts per million in the two sections of the city. Based on your confidence interval in part b, is the statistical significance in part a of practical significance to the city engineers? Explain.Cheaper Airfares Looking for a great airfare? Consumer Reports8 has several hints about how to minimize your costs, which include being flexible about travel dates and times, checking multiple websites, and knowing when to book your flight. One suggestion involved checking fares at "secondary" airports-airports that might be slightly farther from your home, but where fares are lower. For example, the average of all domestic ticket prices at Los Angeles International Airport (LAX) was quoted as $349 compared to an average price of $287 at nearby Ontario International Airport (ONT). Suppose that these estimates were based on random samples of 1000 domestic tickets at each airport and that the standard deviation of the prices at both airports was $200. a. Is there sufficient evidence to indicate that the mean ticket prices differ for these two airports at the a = .05 level of significance? Use the large-sample z test. What is the p-value of this test? b. Construct a 95% confidence interval for ( u - (- ). Does this interval confirm your conclusions in part a
