Suppose the age of buyers were collected and the data follows the bell curve (a normal distribution). The buyers had an average age of 41 years and a standard deviation of 7. You plan to take a random sample of 68 buyers and calculate a sample mean.
Directions: Fill in the blanks and click the button to have your answers graded.
A. Do not round intermediate calculations.
B. For questions 1-3 enter a number between 0 and 1 rounding it to four places.
C. Round your answer to question 4 to two decimal places.
1. What is the probability of finding a sample mean less than 40.96 years? =
2. What is the chance of finding a sample average with a value greater than 41.84 years? =
3. What is the probability of finding a sample average within 2.16 years of the population mean? =
4. What two values of the sample mean cut off the center 16% of the sampling distribution?
Lower Value: = Upper Value: =