An experimental drug has been shown to be 85% effective in eliminating symptoms of allergies in animal studies. A small human study involving eight participants is conducted. What is the probability that the drug is effective on half of the participants?

which of the following are correct? I. One purpose of a double-blind study is to control for researcher bias and placebo effect. II. The main purpose of randomizing individuals to treatment groups is to control for bias. III. Replication is used to help reduce chance variation in experiments.

A random experiment was run 23 times with groups of 24 mice. Each time the experiment was run, 4 mice were initially infected with a disease; the remaining mice were susceptible to contracting the disease.  After one day, they measured the number of number of newly infected mice (not including those originally infected). They found the following frequency table: Newly infected mice Newly infected mice 4 5 6 7 8 9 10 11 Frequency 1 2 2 6 5 4 2 1 Determine the expected probability of transmission for this particular variant of disease. Round your answer to three decimal places.

Researchers investigate how the presence of cell phones influence the quality of human interaction.  Subjects are randomly selected from a population and divided into an experimental group that is asked to leave their phones in the front of the room and a control group that are not asked to leave their cell phones at the front of the room.  Subjects are left alone for 10 minutes and then asked to take a survey designed to measure quality of interactions they had with others in the experiment.  What statistical test is appropriate?

True or False: Suppose I conducted a study using random assignment. This suggests that I took great effort to ensure that all of my subjects had an equal chance of being in either group.

When neither the subject nor those having contact with the subject know the treatment assignment, the study is called     unbiased.     double-blind.     blind.     statistically significant.     randomized.

Determine whether the results below appear to have statistical​ significance, and also determine whether the results have practical significance.   In a study of a weight loss​ program, 6 subjects lost an average of 45 lbs. It is found that there is about a 39​% chance of getting such results with a diet that has no effect. Does the weight loss program have statistical​ significance?     A. ​Yes, the program is statistically significant because the results are unlikely to occur by chance.   B. ​No, the program is not statistically significant because the results are likely to occur by chance.   C. ​No, the program is not statistically significant because the results are unlikely to occur by chance.   D. ​Yes, the program is statistically significant because the results are likely to occur by chance. Does the weight loss program have practical​ significance?     A. ​No, the program is not practically significant because the amount of weight lost is…

A case-control study is conducted to assess the relationship between heavy alcohol use during the first trimester of pregnancy and miscarriage.  Fifty women who suffered miscarriage are enrolled along with 50 who delivered full term.  Each participant’s use of alcohol during pregnancy is ascertained.  Heavy drinking is defined as 4 or more drinks on one occasion.  The data are shown below.     Miscarriage Delivered Full Term Heavy Alcohol Use 14 4 No Heavy Alcohol Use 36 46 a. Compute the odds of miscarriage in women with heavy alcohol use in pregnancy. b. Compute the odds of miscarriage in women with no heavy alcohol use in pregnancy. c. Compute is the odds ratio for miscarriage as a function of heavy alcohol use.

How many subjects in the "patch only" group would you expect not to quit

Teenagers who do not sleep well or long enough may have a higher risk of raised blood pressure, which could lead to cardiovascular disease later in life. The odds of raised blood pressure increase 3.5 times for those who have trouble falling asleep at night or who wake up too early and 2.5 times for those with sleeping periods of fewer than 6.5 hours. A health psychologist is interested in studying teenagers who have diastolic blood pressure scores in the top 20%. Diastolic blood pressure scores for teenagers follow a normal distribution with μ = 72 and σ = 10. Use the Distributions tool to help answer the questions that follow.     The minimum z-score necessary to be in the top 20% of the diastolic blood pressure distribution is z =0.842   .   Use this z-score to determine X, the corresponding diastolic blood pressure score. X = 80.42      This score, X, is the 80th    percentile of diastolic blood pressure scores among teenagers. The percentile rank of this score is 80%…