A consumer advocate wants to find out whether the soft drinks sold at a fast-food restaurant contains less than the advertised 16 ounces. A random sample of 10 independently chosen drinks produced a mean of 16.5 ounces and a standard deviation of 0.4 ounces. Assume that the distribution of serving sizes in the population is normally distributed. a. State the null hypothesis in both words and symbols, use m as the population mean weight of all the drinks labeled 16 ounces at this fast-food restaurant.  b. State the alternative hypothesis in both words and symbols c. Carry out the appropriate test. Explain what conclusion the consumer advocate should reach. d. Explain why no calculations are needed to show that the population mean is not significantly less than 16 ounces.

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 + ...