A student was asked to find a 98% confidence interval for widget width using data from a random sample of size n = 22. Which of the following is a correct interpretation of the interval 13.7 < μ < 27.5? Check all that are correct. The mean width of all widgets is between 13.7 and 27.5, 98% of the time. We know this is true because the mean of our sample is between 13.7 and 27.5. There is a 98% chance that the mean of a sample of 22 widgets will be between 13.7 and 27.5. There is a 98% chance that the mean of the population is between 13.7 and 27.5. With 98% confidence, the mean width of a randomly selected widget will be between 13.7 and 27.5. With 98% confidence, the mean width of all widgets is between 13.7 and 27.5.

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 + ...