If 1 of the men is randomly selected, find the probability that his score is at least 518.6. P(x > 518.6) = Incorrect Enter your answer as a number accurate to 4 decimal places. If 13 of the men are randomly selected, find the probability that their mean score is at least 518.6. P(x-bar > 518.6) = Incorrect Enter your answer as a number accurate to 4 decimal places. Assume that any probability less than 5% is sufficient evidence to conclude that the preparation course does help men do better. If the random sample of 13 men does result in a mean score of 518.6, is there strong evidence to support the claim that the course is actually effective? No. The probability indicates that it is too possible by chance alone to randomly select a group of students with a mean as high as 518.6. Yes. The probability indicates that it is (highly ?) unlikely that by chance, a randomly selected group of students would get a mean as high as 518.6.

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 + ...