Hello,

I hope you are well.

I need help with these question below. I would like step by step.

I am not sure if I am doing right.

5 (a) The number of times a particular piece of machinery breaks down each week over a thirty-week period is recorded in the following data: 2,1,0,4,0,0,3,1,2,4,1,0,3,0,2,4,5,1,0,2,0,1,3,2,4,1,0,0,3,1 (i) Put the data into the form of a frequency distribution (ii) Find the mean number of breakdowns per week. (iii) Find the standard deviation. (iv) Find the median. (b) A production line produces washers which on a sampling of 200 it is found that 158 have diameters within the required tolerance values. Of the remainder it is found that 23 have diameters below and 19 have diameters above the tolerance region. Calculate to four decimal places the probabilities that when randomly selecting a washer and then a second washer without replacement: (i) both have diameters within tolerance. (ii) The first has a diameter below and the second above tolerance (c) A serial code for a ticket consists of 3 numbers from 1 to 9 followed by 2 letters from A to Z. The numbers and letters must all be different. So 654DA and 278FZ are allowed but 552DD and 399AX are not. How many codes are possible