A random sample of 100 students is taken from a larger population of students in a multi-lecture course and the sample mean (average) of their final grades is 66. Suppose it is known that the population standard deviation is 7. You test whether there is significant evidence that the population average differs from 67, using a level of significance of 4%. Choose the most correct statement. Note: You will have to calculate the test statistic by hand, but you can use R to get your pvalue. a. Your pvalue statement is 2P(Z > 1.43), your pvalue is 0.3062 and your decision is to fail to reject Ho. b. Your pvalue statement is 2P(Z > 1.43 ), your pvalue is 0.1531 and your decision is to fail to reject Ho c. Your pvalue statement is 2P(Z > 1.43 ), your pvalue is 0.1531, an

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 + ...