health psychologist is interested in the potential effect that a change in career focus can have on cardiovascular disease for those in high stress jobs. She chooses to study divorce lawyers (a population that averages a mean systolic blood pressure of 142 with a standard deviation of 13) and measures the blood pressure of 23 former divorce lawyers who switched to environmental law. Those 23 lawyers have a mean systolic blood pressure of 131. If all divorce lawyers switched to environmental law, what would you expect the mean systolic blood pressure to be with 99% confidence?   What is the highest estimated value for the mean systolic blood pressure for divorce lawyers who switch to environmental law?

Definition Definition Measure of central tendency that is the average of a given data set. The mean value is evaluated as the quotient of the sum of all observations by the sample size. The mean, in contrast to a median, is affected by extreme values. Very large or very small values can distract the mean from the center of the data. Arithmetic mean: The most common type of mean is the arithmetic mean. It is evaluated using the formula: μ = 1 N ∑ i = 1 N x i Other types of means are the geometric mean, logarithmic mean, and harmonic mean. Geometric mean: The nth root of the product of n observations from a data set is defined as the geometric mean of the set: G = x 1 x 2 ... x n n Logarithmic mean: The difference of the natural logarithms of the two numbers, divided by the difference between the numbers is the logarithmic mean of the two numbers. The logarithmic mean is used particularly in heat transfer and mass transfer. ln x 2 − ln x 1 x 2 − x 1 Harmonic mean: The inverse of the arithmetic mean of the inverses of all the numbers in a data set is the harmonic mean of the data. 1 1 x 1 + 1 x 2 + ...