The typical college freshman spends an average of μ=150 minutes per day, with a standard deviation of σ=50 minutes, on social media. the distribution of time on social media is known to be normal. the proportion of students spending at least 2 hours on social media equals:

The proportion of students spending at least 2 hours on social media equals 0.7257 .

Step-by-step explanation:

Given : The typical college freshman spends an average of μ=150 minutes per day, with a standard deviation of σ=50 minutes, on social media.

The distribution of time on social media is known to be Normal.

Let x be the number of minutes spent on social media.

Then, the probability that students spending at least 2 hours (2 hours = 120 minutes as 1 hour = 60 minutes) on social media would be:

Hence, the proportion of students spending at least 2 hours on social media equals 0.7257 .

Sum of all angles in a triangle is 180 degrees, so x = 180 - 70 - 30 = 80.