Complete Question:
a) Is it plausible that X is normally distributed?
b) For a random sample of 50 such pairs, what is the (approximate) probability that the sample mean courtship time is between 100 min and 125 min?
Answer:
a) It is plausible that X is normally distributed
b) probability that the sample mean courtship time is between 100 min and 125 min is 0.5269
Step-by-step explanation:
a)X denotes the courtship time for the scorpion flies which indicates that is a real - valued random variable, and since normal distribution is a continuous probability distribution for a real valued random variable, it is plausible that X is normally distributed.
b) Probability that the sample mean courtship time is between 100 min and 125 min




From the probability distribution table:


Are you by any chance referring to football? If you are, it is either a play in which by running or passing the offense moves down the field towards the opponent's endzone 15 yards, or it can be obtained by the defense committing an egregious penalty, such as a facemask, unsportsmanlike conduct, or unnecessary roughness.
The denominator of the second fraction can be factored as (a-2)(2a-7), then it becomes doable. You cancel the (2a-7) factors, and are left with:

Do note that you have erased the fact that a≠0 and a≠7/2, so you should always mention that.
To do this you need to work backwards. if you note the number as 'n' you can put
7n = 5600
to find n you simply divide both sides by 7 getting
n = 5600/7
n = 800
Answer: C 7/25
Step-by-step explanation: