Overall, the students’ class attendance days (per year academic) is normally dis

Question

Overall, the students’ class attendance days (per year academic) is normally distributed around 190 days with a standard deviation of 12 days.

a) What’s the probability that the mean number of attendance days will be between 180 and 205?

b) Students that are in the top 6% will receive a 20% off coupon at the “Crazy” cafeteria. What is the minimum number of attendance days that you should have in order to receive such discount?

c) The students at or below the 25% of number of attendance days must attend a counseling session with one of the advisers. At least how many attendance days you should have in order to not have to attend such session?

Explanation / Answer

a) probability that the mean number of attendance days will be between 180 and 205 =P(180<X<205)

=P((180-190)/12<Z<(205-190)/12)= P(-0.8333<z<1.25)=0.8943-0.2023=0.6920

b)for topmost 6% will lie at 94th percentile for which z =1.5548

thefore corresponding score =mean +z*std deviaiton =190+1.5548*12=208.65 days

c)for lowest 25 percentage ; z= -0.6745

thefore corresponding score =mean +z*std deviaiton =190-0.6745*12=181.90 days

please revert for any clariifcation required

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