A group of 74 people enrolled in a weight-loss program that involved adhering to a special diet and to a daily exercise program. After six months, their mean weight loss was 25 pounds, with a sample standard deviation of 9 pounds. A second group of 45 people went on the diet but didn't exercise. After six months, their mean weight loss was 13 pounds, with a sample standard deviation of 8 pounds. Construct a 90% confidence interval for the mean difference in weight losses. Let μ1 denote the mean weight loss of the group with daily exercise. Use tables to find the critical value and round the answers to the nearest integer. A 90% confidence interval for the difference in the mean difference in weight loss, in pounds, is
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
Does this diet help? A group of
pounds. A second group of 45 people went on the diet but didn't exercise. After six months, their mean weight loss was 13 pounds, with a sample standard deviation of 8 pounds. Construct a 90% confidence interval for the mean difference in weight losses. Let μ1 denote the mean weight loss of the group with daily exercise. Use tables to find the critical value and round the answers to the nearest integer.
| A 90% confidence interval for the difference in the mean difference in weight loss, in pounds, is |
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