Refer to Exercise 6.

a. Find a 98% lower confidence bound for the mean time.

b. Someone says that the mean time is greater than 134.3 minutes. With what level of confidence, can this statement be made?

Solution 13E

Step1 of 3:

Let us consider a random variable X it represents the surgery time. Here random variable X follows normal distribution with mean standard deviation and n = 123.

That is

The probability density function of normal distribution is given by

, .

Where,

x = random variable

= mean of X

= variance of X

= standard deviation os X

= mathematical constant and its value is 3.14

Here our goal is:

a). We need to find a 98% lower confidence bound for the mean time.

b). We need to find level of confidence, can this statement be made, by taking the mean time is greater than 134.3 minutes.

Step2 of 3:

a).

Here we have to find 98% CI, let us take .

Now,

= 0.02

Z-scores(are to the right) is given by

is obtained from standard normal table(area under normal curve). In standard normal table...