The average length of a flight by regional airlines in the United States has been reported as 464 miles. If a simple random sample of 30 flights by regional airlines were to have a mean of 476.9 miles and a standard deviation of 42.8 miles, what would be the test statistics (t-value) if we are to test whether this tend to cast doubt on the reported average of 464 miles or not

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Answer:

The t-value is t = 1.65.

Step-by-step explanation:

The test statistic is:

[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

The average length of a flight by regional airlines in the United States has been reported as 464 miles.

This means that the null hypothesis is [tex]H_{0}: \mu = 464[/tex].

Simple random sample of 30 flights by regional airlines were to have a mean of 476.9 miles and a standard deviation of 42.8 miles

This means that [tex]n = 30, X = 476.9, s = 42.8[/tex]. So

[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]

[tex]t = \frac{476.9 - 464}{\frac{42.8}{\sqrt{30}}}[/tex]

[tex]t = 1.65[/tex]

The t-value is t = 1.65.