Question

at a particular university, statistics students miss a mean of 2.1 days of school each semester with a standard deviation of 2.5 days. what is the probability that the mean number of days missed for a random sample of 64 students will be more than 3?

Answer 1

Solution :

Given that ,

mean = = 2.1

standard deviation = = 2.5

= / n = 2.5 / 64 = 0.3125

P( > 3) = 1 - P( < 3)

= 1 - P[( - ) / < (3 - 2.1) / 0.3125]

= 1 - P(z < 2.88)

= 1 - 0.998

= 0.002

Probability = 0.002