Alzheimer’s disease increases in frequency with an increase in age and is responsible for deficits in memory, thinking, judgement and reasoning. Reports show that 10% of Americans over the age of 65 have Alzheimer’s disease. A researcher believes that this proportion is increasing over time and conducts a c hypothesis test. Out of the 100 Americans over the age of 65 in her sample, 15 of them have the disease. Is this enough evidence to show the researcher’s claim is true? Test at 0.05 alpha level.

There is popular belief that herbal remedies such as Ginkgo Biloba and Ginseng may improve learning and memory in healthy adults. In a new study, a researcher obtains a sample of n = 36 participants and has each person take the herbal supplements every day for 90 days. The researcher wants to assess whether memory scores will increase for those taking the herbal remedies. At the end of 90 days, each person takes a standardized memory test. For the general population, scores from the test are normally distributed with a mean of μ = 80 and a standard deviation of σx = 18. The sample of research participants had an average of 84. a. Identify the independent variable. b. Identify the dependent variabl

In 1990, 58% of Americans 18 years old and older reported they have a great deal of concern regarding air pollution. A recent poll found that 592 of 1004 Americans 18 years old or older stated that they have a great deal of concern regarding the level of air pollution in American. Is there evidence to conclude that the current proportion of Americans having a great deal of concern about the level of air pollution in America is different from the 1990 proportion, with a 10% level of significance?  State the null hypothesis, alternative hypothesis, test statistic, p-value and conclusion.

Researchers wondered if there was a difference between males and females in regard to some common annoyances. They asked a random sample of males and females, the following question: "Are you annoyed by people who repeatedly check their mobile phones while having an in-person conversation?" Among the 505 males surveyed, 171 responded "Yes"; among the 522 females surveyed, 202 responded "Yes." Does the evidence suggest a higher proportion of females are annoyed by this behavior? Complete parts (a) through (g) below. C -0.0484 ő 0 0.0484 (e) Determine the P-value based on the model from part (d). First find the test statistic for this hypothesis test. (Round to two decimal places as needed.)

A graduate student is interested in how viewing different types of scenes affects working memory. For his study, he selects a random sample of 36 adults. The subjects complete a series of working memory tests before and after walking in an urban setting. Before the walk, the mean score on the test of working memory was 9.1. After the walk, the mean score was 1.4 higher. The graduate student has no presupposed assumptions about how viewing different types of scenes affects working memory, so he formulates the null and alternative hypotheses as: H00 : μDD = 0 H11 : μDD ≠ 0 Assume that the data satisfy all of the required assumptions for a repeated-measures t test. The graduate student calculates the following statistics for his hypothesis test: Mean difference (MDD) 1.4 Estimated population standard deviation of the differences (s) 1.6 Estimated standard error of the mean differences (sMDMD) 0.2667 Degrees of freedom (df) 35 The t statistic 5.25 The critical values of t…

Researchers wish to study the effect of daily brain teasers on a person's intelligence. The researchers randomly choose 20 students from their local college campus. Day one of the test, every student is given an IQ test. The students are then randomly divided into Group A and Group B (10 students each). Group A is given daily brain teasers, while Group B were not instructed to participate in anything outside their normal routine. At the end of a 30 day period, each member of the group takes an IQ test. The students are aware of what group they are in, but the researchers have no idea until the results are given. The test given to Group A would be considered the Control Treatment Variable Placebo

In June 2015, Gallup conducted a poll of a random sample of 14,683 adults to determine the well-being of people living in the United States. One question asked, "Did you exercise at least 30 minutes for 3 or more days in the past week?" In the survey, 58.9% of males and 52.7% of females responded yes to this question. Which of the following is true about this scenario? A. O 58.9% and 52.7% are both parameters. B. O 58.9% and 52.7% are both statistics. C. If we took another random sample of 14,683 adults, we would expect to get the exact same results.

A political scientist claims that 38% of first-year college students characterize themselves as being “moderate” or “middle of the road” as far as their political affiliation is concerned.   Believing this claimed value is too high, you survey a random sample of 400 first-year college students and find that 120 characterize themselves as being “moderate” or “middle of the road.”    Based on this information, what will the test statistic be? Choose the answer below that is closest to what you calculate, and try not to do a lot of rounding until you get to the very end of your calculations.   1. -0.3 2. -1.2 3. -2.6 4. -3.3 5. None of the other answer options are correct because the test statistic should be positive, not negative.

In an observational study it was found that people who had received the flu shot this year had better blood pressure readings, on average, than people who did not.  Can it be claimed that the flu shot is the cause of the lower overall blood pressure?  Why or why not?

Based on information from Harper's Index, 37 out of a random sample of 100 adult Americans who did not attend college believe in extraterrestrials. However, out of a random sample of 100 adult Americans who did attend college, 47 claim that they believe in extraterrestrials. Does this indicate that the proportion of people who attend college and who believe in extraterrestrials is higher than the proportion who did not attend college? (a) State the hypotheses in plain language. (b) Fill in the table below, then enter this table in the left side of the Rossman-Chance applet. No college College Total Believe in ETs 84 Did not believe in ETs 116 Total 100 100 200 (c) Compute the point estimate for the difference in the proportion believing in extraterrestrials between those not attending college and those attending college. Pne – Pe = (d) Complete at least 1000 simulations in the Rossman-Chance app 2 and report your findings below. (For help with the applet, refer to the e "Using the…