Disks of polycarbonate plastic from a supplier are analyzed for scratch and shock resistance. the results from 100 disks are summarized as follows:
shock resistance
scratch resistance high low
high 70 9
low 16 5
let a denote the event that a disk has high shock resistance, and let b denote the event that a disk has high scratch resistance. if a disk is selected at random, determine the following probabilities. input your answers in the fractional form (do not simplify).
p(a)=86/100
p(b)=79/100
p(a')=7/50
p(a u b)=95/100
p(a' u b)=

If your score on your next statistics test is converted to a z score, which of these z scores would you prefer: minus2.00, minus1.00, 0, 1.00, 2.00? why? a. the z score of 2.00 is most preferable because it is 2.00 standard deviations above the mean and would correspond to the highest of the five different possible test scores. b. the z score of 0 is most preferable because it corresponds to a test score equal to the mean. c. the z score of minus2.00 is most preferable because it is 2.00 standard deviations below the mean and would correspond to the highest of the five different possible test scores. d. the z score of minus1.00 is most preferable because it is 1.00 standard deviation below the mean and would correspond to an above average