Suppose that a randomized comparative experiment studies the effect of diet on blood pressure. Researchers divide 54 healthy white males at random into two groups. One group receives a calcium supplement, and the other group receives a placebo. At the beginning of the study, the researchers measure several variables on the subjects. The average seated systolic blood pressure of the 27 members of the placebo group is reported to be = 114.9, with a standard deviation of s= 9.3. Give a 95% confidence interval for the mean systolic blood pressure of the population from which the subjects were recruited. Report your interval values to one decimal place. 95% confidence interval: The recipe you used to calculate the 95% confidence interval requires an important assumption about the 27 men who provided the data. What is this assumption? The number of men in the in the placebo group are randomly chosen from the population of healthy white males. The subjects in the placebo group are a simple random sample (SRS) of healthy white males. The number of men in the placebo group are reasonably small enough sample to use the formula for a confidence

A physical therapist wanted to know whether the mean step pulse of men was less than the mean step pulse of women. She randomly selected 54 men and 70 women to participate in the study. Each subject was required to step up and down a 6-inch platform. The pulse of each subject was then recorded. The following results were obtained. Two sample T for Men vs Women N Mean StDev SE Mean Men Women 98% CI for mu Men - mu Women (- 12.20, - 1.00) T-Test mu Men = mu Women (vs H2 O C. Ho: H1 = H2; Ha: H1 #H2 (b) Identify the P-value and state the researcher's conclusion if the level of significance was a = 0.01. What is the P-value? P-value =

A researcher is interested in examining the difference in the average egg incubation temperature of two lizards in North Carolina, the native green anoles versus the invasive brown anoles. To investigate this, she takes two random samples from both of the lizard populations and calculates the average egg incubation temperature, standard deviation, and sample size for each of the two samples.  The average incubation temperature for the 25 sampled brown anoles is 83.2 degrees Fahrenheit, with a sample standard deviation of 20.2 degrees Fahrenheit.  The average incubation temperature the 28 samples green anoles is 80.1 degrees Fahrenheit, with a sample standard deviation of 17.4 degrees Fahrenheit. She has also determined that the two samples do not exhibit strong skewness and appear approximately normal.  Determine the standard error for the 99% confidence interval for the difference between the true mean incubation temperatures for the two different anole species, μ1−μ2. Give your…

A researcher wonders whether the recession has changed variability in family size in his city. Before the recession, the mean was 3.7 and the standard deviation was 1.76. The researcher randomly selects 41 families from a population that is normally distributed. His sample has a mean of 3.1 and a standard deviation of 1.45. Test the claim that the standard deviation in size has changed at the αα=.05 significance level.