Answer: a) mean= 569 = 9:29am
SD= +/- 17
b) P= 11/34 = 0.32
Step-by-step explanation:
since it's a continuous uniform distribution all time between 9:12 and 9:46 have equal frequency of occurrence.
9:12= 9×60min + 12= 552mins
9:46= 9×60min + 46 = 586mins
9:35= 9×60min + 35 = 575mins
Therefore, the mean is given by,
Tm= (552+586)/2= 569mins = 9:29am
Standard deviation = √{(552-569)sq + (586-569)sq}/2
= √(17×17)+(17×17) /2
=17 =+/-17
Probability of arriving late = 586-575 / 586-552 = 11/34
= 0.32