Five pulse rates are randomly selected from a set of measurements. The five pulse rates have a mean of 69.8 beats per minute. Four of the pulse rates are 50, 78, 67, and 84. a. Find the missing value. b. Suppose that you need to create a list of n values that have a specific known mean. Some of the n values can be freely selected. How many of the n values can be freely assigned before the remaining values are determined? (The result is referred to as the number of degrees of freedom.) a. The missing value is beats per minute. (Type an integer or a decimal. Do not round.) b. Select the correct choice below and fill in the answer box to complete your choice. (Type an expression using n as the variable.) OA. Of the n values, can be freely selected because the remaining value(s) must be equal to the known mean. OB. Of the n values, can be freely selected because the remaining value(s) can be expressed in terms of the mean, median, and midrange of the assigned values. OC. Of the n values, can be freely selected because the remaining value(s) can be expressed in terms of the assigned values and the known mean.