A researcher wants to calculate the prevalence of Alzheimer’s among members of a specific community who are 65 years of age and older. The researcher needs to know how many individuals who are 65 years of age or older need to be recruited for the study to ensure the estimated prevalence will be within 1.0% of the true proportion. Calculate the sample size needed by the researcher if a national study has shown 10.73% of individuals 65 years of age have Alzheimer’s based on a 95% CI of the true proportion.

In the US, 45.1% of all people have type O blood, 39.6% have type A blood, 10.9% have type B blood and 4.4% have type AB blood. A researcher wants to see if the distribution of blood type is different for millionaires. The table below shows the results of a random sample of 614 millionaires. What can be concluded at the significant level of a = 0.05. For this study, we should use Chi-Square test for Goodness of Fit Your friend Caroline helped you with the null and alternative hypotheses... Ho : The distributions of blood types are the same between the general population and the millionaires. Ha: The distributions of blood types are NOT the same between the general population and the millionaires. You drew 614 samples, and the observed frequencies are recorded below. Please complete the table (round answers to at least 4 decimal places). Blood Type 0 A B AB Observed Count 274 230 57 53 Expected Count Click Download CSV to download csv file of data or copy/paste the data into Excel.…

A substance abuse counselor wants to demonstrate the effect of situational stress on alcohol cravings. He recruits two groups of men who are similar in respect to history of alcohol use and demographic variables. He divides them in to two groups. In one group(n=11), the men are exposed to a stressful situation and then asked to complete a measure rating their alcohol cravings on a scale from 0-10, where 0 representsno cravings and 10 represents intense cravings. In the second group (n=10), the men are exposed to a neutral situation and asked to complete the same measure. What test  and graph should I create to find out if a stressful situation result in more intense alcohol cravings than a non-stressful situation?

In random samples of 900 men and 400 women it is found that 99 men and 36 women suffer from kidney stones. Is there statistical evidence that the proportion of male kidney stone sufferers is greater than the proportion of female kidney stone sufferers? Use 5% significant level.

GMU uses a robot food delivery service which now has been utilized in the City of Fairfax. One of the potential benefits of this service is to help the busiest students eat breakfast. Research has shown that about 80% of college students skip breakfast due to busy schedules and other reasons. Initial data were collected from a random sample of 595 Mason students who utilize the robot food delivery service and are presented in StatCrunch.    Show the full calculation of the sample proportion by including the number of students who skipped breakfast, the total number of students sampled, and the value of the sample proportion. Present this sample proportion as a decimal rounded to four decimal places. Frequency table results for Breakfast?Count = 595 Breakfast? Frequency Relative Frequency 0 142 0.23865546 1 453 0.76134454

Color blindness, or dyschromatopsia, is a form of genetic deficiency in color perception. The condition is much more prevalent among males than females, pointing to a genetic connection with the X chromosome. The frequency of dyschromatopsia in the Caucasian American male population is about 7%. However, it is thought that this proportion might be smaller among males of other ethnicities. We want to estimate the proportion of Asian American males who are color-blind. How large a sample size do we need in order to obtain a 95% confidence interval with a margin of error no greater than 5%, or 0.05? Use 0.5 for p̂.

The state highway department is studying traffic patterns on one of the busiest highways in the state. As part of the study. the department needs to estimate the average number of vehicles that pass an intersection each day. One of the department's officer (Officer A) claims that on average, more than 15,000 cars passing the intersection. On the other hand. Officer B claims that on average, 18,000 cars passing the intersection. Meanwhile, a random sample of 64 days gives a sample mean of 14,205 cars and a sample standard deviation of 1,010 cars. Test both claim at 0.05 level of significance. Use the critical value approach and show the complete calculation steps for each testing. Whose claim is true? Testing Officer A's claim Step 1: State the hypotheses Step 2: Find critical value and state the decision rule Step 3: Compute the test value Step 4: Make decision Step 5: Conclusion Testing Officer B's claim Step 1: State the hypotheses Step 2: Find critical value and state the decision…

The American Water Works Association reports that, The average household water usage is more than 10 gallons per day. However, in a pandemic like this, it is suspected that there is a change in household water consumption. A researcher conducted a survey and took samples of 12 household heads and asked about the use of the gallon water. The data obtained are as follows: 74, 8, 13, 17, 13, 15, 12, 13, 15, 16, 9, 7. If it is known that the data is normally distributed. Use a significance level of 5% to test whether the average household water use has increased (greater than 10 gallons)? What will happen if the household's water use increases by 5% from the previous one? Analyze your answer and come up with a conclusion!