step by step help

I do have a TI 84 calculator

Suppose that a category of world class runners are known to run a marathon (26 miles) in an average of142minutes with a standard deviation of13minutes. Consider 49 of the races.

LetX

= the average of the 49 races.

• Part (a)
• Give the distribution ofX.
• (Round your standard deviation to two decimal places.)

• Part (b)
• Find the probability that the average of the sample will be between139and143minutes in these 49 marathons. (Round your answer to four decimal places.)
• Part (c)
• Find the60thpercentile for the average of these 49 marathons. (Round your answer to two decimal places.) in minutes
• Part (d)
• Find the median of the average running times. in minutes