Question

A report in 2020 indicates that Americans between the ages of 8 and 18 spend an average of μ=7.5 hours per day using some sort of electronic device such as smart phones, computers, or tablets. Assume that the distribution of times is normal with a standard deviation of 2.5 hours and find the following values. What is the probability of selecting an individual who uses electronic devices more than 12 hours a day?

Answer 1

The probability of selecting an individual who uses electronic devices more than 12 hours a day is approximately 3.59%.

Step-by-step explanation:

To find the probability of selecting an individual who uses electronic devices more than 12 hours a day, we can use the normal distribution. We have the mean (μ) of 7.5 hours per day and the standard deviation (σ) of 2.5 hours.

Since we're looking for the probability of using more than 12 hours, we need to find the z-score of 12 using the formula z = (x - μ) / σ. Substituting in the values, we get z = (12 - 7.5) / 2.5 = 1.8.

Using a standard normal distribution table or calculator, we can find that the probability of selecting an individual who uses electronic devices more than 12 hours a day is approximately 0.0359 or 3.59%.