Question

Part 1: A manufacturer knows that their items have a normally distributed lifespan, with a mean of 4.4 years, and standard deviation of 0.9 years.

The 2% of items with the shortest lifespan will last less than how many years?

Part 2: Engineers must consider the breadths of male heads when designing helmets. The company researchers have determined that the population of potential clientele have head breadths that are normally distributed with a mean of 6.1-in and a standard deviation of 1-in. Due to financial constraints, the helmets will be designed to fit all men except those with head breadths that are in the smallest 2.3% or largest 2.3%.

What is the minimum head breadth that will fit the clientele?
min =

What is the maximum head breadth that will fit the clientele?
max =

Part 3: The combined SAT scores for the students at a local high school are normally distributed with a mean of 1527 and a standard deviation of 295. The local college includes a minimum score of 1616 in its admission requirements.

What percentage of students from this school earn scores that satisfy the admission requirement?
P(X > 1616) =  %

Answer 1