Question

The time required to finish a test in normally distributed with a mean of 80 minutes and a standard
deviation of 15 minutes. What is the probability that a student chosen at random will finish the test in more
than 110 minutes?
16%
34%
82%
2%

Answer 1

Do u need help or do u want answer?

Answer 2

both please, I want to understand it as well.

Answer 3

if you can

Answer 4

ok : ) let me see

Answer 5

The time required to finish a test in normally distributed with a mean of 80 minutes and a SD = 15 minutes

110 would be 2 SD greater than the mean





P( x>110) = P(t> 2) = (1 - .954)/2 = .023



For the normal distribution:

one standard deviation from the mean accounts for about 68.2% of the set

two standard deviations from the mean account for about 95.4% *****

and three standard deviations from the mean account for about 99.7%.

Answer 6

wait so what's the answer then?

Answer 7

i don't understand what happened