Lisa has collected data to find that the number of pages per book on a book shelf has a normal distribution. What is the probability that a randomly selected book has fewer than 133 pages if the mean is 189 pages and the standard deviation is 28 pages? Use the empirical rule. Enter your answer as a percent rounded to two decimal places if necessary.

2.5% probability that a randomly selected book has fewer than 133 pages.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 189 pages

Standard deviation = 28 pages

What is the probability that a randomly selected book has fewer than 133 pages?

133 = 189 - 2*28

So 133 is two standard deviations below the mean.

The Empirical Rule states that 95% of the measures are within 2 standard deviations of the mean. The other 5% is more than two standard deviations distant from the mean. The normal distribution is symmetric, which means that of those 5%, 2.5% are more than 2 standard deviations below the mean and 2.5% are more than 2 standard deviations above the mean.

This means that there is a 2.5% probability that a randomly selected book has fewer than 133 pages.

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950