Hello i am doing assignment in my math 20-2 class. The question is: data collected of cars passing on the road revealed that the average speed was 90 km/h with a standard deviation of 5 km/h and the data which is normally distributed a policeman is assigned to set photo radar on the road in which the posted speed limit is 80 km/h it's 600 cars pass the photo radar in the police man sets the camera so that only those exceeding the speed limit by 10% are photographed, then how many drivers can the police expect to ticket? Can someone please tell me how to solve this?

3 answers

Z = (score-mean)/SD

If the camera is set at 10% above speed limit = 88 km/h.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability in the larger portion related to the Z score. Multiply by 600.
Ok but before we start we usually write downwhat the mean equals, standard deviation and X. Im still confused on which one would be the mean.
I found that the inversenorm is 83.5922, what do i do after this?