A factory process requires 3 steps to finish a product. The steps each have a mean completion time of A= 10 seconds and a standard deviation of o = 5 seconds. The time it takes to complete each step is independent from the other steps. Let T be the total completion time for the 3 steps. Find the standard deviation of T.

Choose 1

OT = 15 seconds

Or = 75 seconds

or 15 seconds

or = v75 seconds

I'll give brainliest if you answer right : )

The number of chocolate chips in an 18-ounce bag of chocolate chip cookies is approximately normally distributed with a mean of 1252 chips and standard deviation 129 chips. (a) what is the probability that a randomly selected bag contains between 1100 and 1500 chocolate chips, inclusive? (b) what is the probability that a randomly selected bag contains fewer than 1125 chocolate chips? (c) what proportion of bags contains more than 1225 chocolate chips? (d) what is the percentile rank of a bag that contains 1425 chocolate chips?

Ageologist had two rocks on a scale that weighed 4.6 kilograms together.rock a was 0.5 of the total weight.how much did rock a weigh?