Of all the weld failures in a certain assembly, 85% of them occur in the weld metal itself. a sample of 10 weld failures is examined. assume independence of weld failures.(a) what is the probability that fewer than four of them are base metal failures? (b) what is the probability that at least nine of them are base metal failures? (c) find the mean and standard deviation of the number of base metal failures.

Use the spider tool located on page 1 of this activity to draw a 12-pointed star for the new logo. (hint: if the spider rotates 360 degrees -- or 720 degrees or 1080 degrees -- she will be facing in the same direction in which she started. when the spider is done drawing, you want her to be facing in the same direction in which she started. she'll be making 12 rotations, all the same size, so each rotation must be some multiple of 360/12 = 30 degrees.) urgently. been stuck on this problem for around 45 minutes now.! it should be easy if you're smart enough