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the average length of time for an individual to complete (keep records for,

learn, prepare, copy, assemble, and send) IRS Form$1040$ is $10.53$hours (without any attached schedules).

The distribution is unknown.

Let us assume that the standard deviation is two hours.

The definition of random variable is given by,

$X=$length of time for an individual to complete IRS form $1040$, in hours.

In other words, the sample random variable is defined as, $\overline{X}=$the mean length of time for a sample of $36$taxpayers to complete IRS form.

The random variable can be expressed as,$X~N\left(10.53,\frac{1}{3}\right)$normal distribution.

On taking normal CDF, we get the probability is$0$

Yes. I would be surprised because the probability is almost$0$

If one taxpayer finished his or her Form in more than twelve hours, the probability is about$0.2312$

No. I would not be totally surprised because the probability is $0.2312$