In a certain region, suppose the ages of smartphone users approximately follow a normal distribution with approximate mean and standard deviation of 39.9 years and 9.1 years, respectively. determine the probability that a random smartphone user is at most 48 years old. • round your answer to four decimal places.

0.8133.

Step-by-step explanation:

We have been given that the ages of smartphone users approximately follow a normal distribution with approximate mean and standard deviation of 39.9 years and 9.1 years, respectively.

First of all, we will use z-score formula to find z-score of 48.

, where,

= z-score,

= Sample score,

= Mean,

= Standard deviation.

Substitute the given values:

Now, we will need to find the probability of z-score less than or equal to 0.89 as:

Using normal distribution table, we will get:

Therefore, the probability that  a random smartphone user is at most 48 years old would be 0.8133.

mean, 40.6

step-by-step explanation:

a

step-by-step explanation: