Question

5. Capability growth often occurs in aerospace programs. Consider the possibility that SpaceX wants do deliver more payload to orbit and is developing an upgraded Falcon 9, also with 9 engines. Each individual engine will now have an additional 10,000 lbs of thrust, so that each has sea-level thrust of 200,000 lbs. The standard deviation of the thrust of the population of individual engines is expected to grow to 1650 lbs.
6. 1. Calculate the 95% confidence interval around a mean of 200,000 lbs for a sample of 9 engines.
7. 2. Calculate the 95% confidence interval around a mean of 200,000 lbs for a sample of 9 engines if we now assume the standard deviation is based on the sample.
   3. You want your engines to average a minimum of 199,500 lbs. Assume you run a hypothesis test for the mean of a sample of 9 engines. Your null hypothesis is that the mean is less than 199,500 and your alternate hypothesis is that the mean is more than or equal to 199,500 lbs. After analysis, if your p-value is 0.07, what is the result of the test and your conclusion regarding the engines and why? (You don’t need to do any calculations for this part, just use the data provided in the problem for your conclusion)

Answer 1

Falcon-9 with 9 engine

Given mean of thrust X= 20,000 lbs

Population Standard deviation = 1650 lbs

A. Finding 95% confidence interval

n= 9

The sample mean is in the interval of

X (marginal error)

X Zvalue× (SD/√n)

When we use the level of significance= 0.05

Then the p value is in the acceptance region

That is mean load is less than 199500.