Question

a research engineer for a tire manufacturer is investigating tire life for a new rubber compound and has built 16 tires and tested them to end-of-life in a road test. the sample mean and standard deviation are 60,139.7 and 3517.57 kilometers. can you conclude, using ????

Answer 1

There is no sufficient evidence to indicate the true standard deviation is less than 4000

What is standard deviation ?

The standard deviation is a statistic that expresses how much variation or dispersion there is in a set of values. While a high standard deviation suggests that the values are dispersed over a wider range, a low standard deviation suggests that the values tend to be close to the set mean.

given that n = 16

x = 60139.7

s = 3718.06

∝ = 0.05

To test the hypothesis

H0 : = 4000

H1 :  < 4000 (claim)

test statistics

x² = ((n-1)s²) / H0²

   = (15 * 13823970.16) / (16000000)

   = 12.96

P- value = P [x² < 12.96]           DF = n-1 = 15

             = 0.3946

0.1 < P-value <0.5

To learn more about standard deviation from the given link  

https://brainly.com/question/475676

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