A weight loss study found that the intervention group had an average weight loss of 4 kg as compared to the control group.The confidence interval showed the range of possible results to be from 12kg lost to 4 kg gained.What is the best interpretation of this information?Question 9Answera.The control group lost more weight than the intervention group and this was a significant result.b.The intervention resulted in an average weight loss of 4kg and this result was significant.c.The intervention did not work.d.The intervention resulted in an average weight loss of 4kg but this result was not significant.

A study produced the following result:RR 0.4 (95% CI 0.2 to 0.6).What information can you gather from this result?Question 7Answera.The intervention achieves a better outcome than the comparison, although there is not a statistically significant difference between the groupsb.The intervention achieves a better outcome than the comparison, with the difference statistically significantc.The intervention achieves a better outcome than the comparison, it is not a statistically significant difference, and the sample size is larged.The intervention achieves a better outcome than the comparison

A health spa has advertised a weight-reducing program and has claimed that the average participant in the program loses is about 17 pounds. A somewhat overweight executive is interested in the program but is sceptical about the claims and asks for some hard evidence. The spa allows him to select randomly the records of 10 participants and record their weights before and after the program. These data are recorded below: weight Before 189 202 220 207 194 177 193 202 208 233 After 170 179 203 192 172 161 174 187 186 204 Construct the 99% confidence interval on the mean difference of weight before and after the program. Does the claim from the health spa is true? Explain.

A student was asked to find a 95% confidence interval for weight of their backpacks in pounds using data from a random sample of size n = 20. Which of the following is a correct interpretation of the interval 3.1 < μ < 8.6? Assume the population is normally distributed.With 95% confidence, the weight of a randomly selected backpack will be between 3.1 and 8.6 pounds.There is a 95% chance that the mean of a sample of 20 backpacks will weigh between 3.1 and 8.6 pounds.There is a 95% chance that the weight is between 3.1 and 8.6.With 95% confidence, the mean weight of all backpacks is between 3.1 and 8.6 pounds.The sample mean weight of all backpacks is between 3.1 and 8.6 pounds, 95% of the time. We know this is true because the mean of our sample is between 3.1 and 8.6.

An experiment will be conducted to test the effectiveness of a weight-loss supplement. Volunteers will berandomly assigned to take either the supplement or a placebo for 90 days, with 12 volunteers in each group. Thesubjects will not know which treatment they receive. At the end of the experiment, researchers plan to calculatethe mean weight loss for each of the two groups and to construct a two-sample t-confidence interval for thedifference of the two treatment means. Which of the following assumptions is necessary for the confidenceinterval to be valid?(A) The sample size is greater than or equal to 10 percent of the population size.(B) Each of the two groups has at least 5 successes and at least 5 failures.(C) The distributions of weight loss of the two treatments are approximately normally distributed.(D) The volunteers in the supplement group are paired with volunteers in the placebo group.(E) The expected number of people who lose weight in each group is at least 5.

An advertisement for a popular weight-loss clinic suggests that participants in its new diet program lose, on average, more than 10 pounds. A consumer activist decides to test the authenticity of the claim. She follows the progress of 29 women who recently joined the weight-reduction program. She calculates the mean weight loss of these participants as 10.8 pounds with a standard deviation of 1.6 pounds. The test statistic for this hypothesis would be __________.Multiple Choice−3.023.02−2.69