The shape of the distribution of the time required to get an oil change at a 15-minute oil-change facility is unknown. However,
records indicate that the mean time is 16.2 minutes, and the standard deviation is 3.4 minutes.(a) What is the probabilty that a random sample of n = 40 oil changes results in a sample mean time less than 15 minutes?Round to 4 decimal.(b) Suppose the manager agrees to pay each employee a $50 bonus if they meet a certain gol. On a typical Sunday, the oil-change facility will perform 40 oil changes between 10 A.M. and 12 P.M. Treating this as a random sample, what mean oil-change time would there be a 10% chance of being at or below? This will be the goal established by the manager.There is a 10% chance of being at or below a mean oil change time of ? minutes.Round to 1 decimal.
Here we can use fact than we can multiply fraction by inverse of fraction instead of dividing it. Inverse of 1/3 is 3/1 Lets multiply it - its our result
- its our result