Diane's Tree Trimming Service has trimmed hundreds of trees in the Greater Denver area. The time it takes to trim a tree is normally distributed with a mean of 32 minutes and a standard deviation of 5 minutes (Use this distribution to answer the next several questions). What percent of trees get trimmed between 28.5 and 31.5 minutes? Group of answer choices 21.82% 75.80% 70.22% 29.78%

And we can find this probability with this difference:

And in order to find these probabilities we use tables for the normal standard distribution, excel or a calculator.

So then the best answer would be 21.82 %

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

Solution to the problem

Let X the random variable that represent the time it takes to trim a tree of a population, and for this case we know the distribution for X is given by:

Where and

We are interested on this probability

And the best way to solve this problem is using the normal standard distribution and the z score given by:

If we apply this formula to our probability we got this:And we can find this probability with this difference:

And in order to find these probabilities we use tables for the normal standard distribution, excel or a calculator.

 So then the best answer would be 21.82 %

a

step-by-step explanation:

all group life insurance is term insurance. actually it is annual renewable term and it is rated on the average age and claims experience of the entire group, which is called "experience rating." remember, this type of insurance has a 31-day grace period and is convertible to whole life upon leaving employment. a contributory group plan requires that both the employer and the employees pay part of the premium. at least 75% of those eligible must participate, so the group is sure to get most of the healthy employees as well as those that are sick.

step-by-step explanation: