A researcher wanted to compare that activity of pet dogs living in the city and pet dogs living in the suburbs. To test that, he collected a sample of 21 dogs from the city and 21 dogs from the suburbs and measured how long they were active on a random day (in minutes). The mean activity time for the city dogs’ sample was M1 = 116 with a variance of S1 2 = 400. For the suburb dogs’ sample, the mean was M2 = 150 with a variance of S2 2 = 625. a. Which test should be used to analyze the dat

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 + ...