Refer to Exercise 2. Find a 98% upper confidence bound for the proportion of residences that reduced their water consumption.

Answer:

Step 1 of 3:

Here our aim is to find a 98% upper confidence bound for the proportion of residences that reduced their water consumption.

Step 2 of 3:

Let X = The number of residences that reduced their water consumption.

Therefore,

Where, the sample size n = 100, X = 73.

A 98% upper confidence bound for ‘p’ is given by

Where,

= 100 + 4

= 104.

=

= 0.72115

Then,

From the statistical table the z-value for 98% confidence interval is 2.32.

=

= 0.811.

Step 3 of 3:

Conclusion:

Therefore, a 98% upper confidence bound for the proportion of residences that reduced their water consumption is 0.811.