Question

Anybody good at statistics. i have three questions i want to check over, i can do , not the third one

Answer 1

What are they?

Answer 2

a) BearCo produces alutin (and alloy of aluminium and tin) bearings for truck engines. Prior to shaping, ingots of alutin pass through a rolling mill, where they are reduced to a mean thickness of 3.05 mm , with a standard deviation of 0.025 mm. The alutin ingots can be shaped if their thickness is between 2.97 mm and 3.08 mm. These ingots are described as in spec. If they are outside that range they are out of spec and need to be melted down and recast. a) Assuming that alutin ingot thickness follows a normal distribution, determine the probability that a randomly selected ingot is ”in spec”.

b) Next Part is BearCo needs 48 ingots for a bearing production run. If they roll 50 ingots, determine the probability that they will have enough “in spec” ingots for the production run.

C) If BearCo need 300 “in spec” ingots for a production run, determine the minimum number that should rolled, such that there is at least a 95% probability that they will have enough.

Answer 3

i can do part a) using a normal distribution, and part b i used a binomial distribution

Answer 4

I haven't a clue how to do part c)

Answer 5

it looks like it's related to part B

Answer 6

yeah, ok so let me show you my work

Answer 7

a) TI 84: normalcdf (2.97,3.08,3.05, .025)

Answer 8

thats the area underneath the normal distribution from 2.97 to 3.05