The fan blades on commercial jet engines must be replaced when wear on these parts indicates too much variability to pass inspection. If a single fan blade broke during operation, it could severely endanger a flight. A large engine contains thousands of fan blades, and safety regulations require that variability measurements on the population of all blades not exceed σ2 = 0.18 mm2. An engine inspector took a random sample of 71 fan blades from an engine. She measured each blade and found a sample variance of 0.32 mm2. Using a 0.01 level of significance, is the inspector justified in claiming that all the engine fan blades must be replaced?

All the engine fan blades must be replaced

Step-by-step explanation:

From the question we are told that:

Sample size

Variance

Level of significance

Generally the hypothesis is

The test hypothesis is

Null  

Alternative

Generally the equation for Chi distribution  is mathematically given by

The test statistic is  

Since

Critical Value

Hence, we Reject ,Given that 124.4 is Greater than 100.4252

Therefore

All the engine fan blades must be replaced

question: how many people can she serve?

answer: she can serve 16.66666667 people. so she can only give 16 people a complete serving.

question: does she have enough ice cream for her guests?

answer: no. explanation: she only has enough for 16 people to have a full serving. however, she can give a 17th person a partial serving.