A manufacturer of computers claims its newest model has a mean battery life of 10 hours,...

A manufacturer of computers claims its newest model has a mean battery life of 10 hours, although normally distributed variations in computer production will cause some units to have more or less battery life. A consumer advocacy group is concerned the true mean is less and is constructing a hypothesis test at the 95% significance level to evaluate the claim. In their testing for battery life, a sample of 25 randomly selected units gave a sample mean of ̄x25 = 9.6, with sample standard deviations25= 0.8. (a) Clearly state the null hypothesis and alternate hypothesis for the test. (b) Determine the appropriate test statistic and compute it. (c) On the basis of this test statistic value, what conclusion does the test reach regarding the battery life claims? (d) If the conclusion reached happens to be incorrect, would it be a type I error or type II error? Explain.

Expert Solution

d) Since we reject the null hypothesis, one can make a Type I error, i.e. rejecting null hypothesis when it is actually true.

orchestra answered 2 years ago

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