Crawford Industries Purchases Step-Down Electrical Converters from Two Suppliers

question 30

Multiple Choice

Crawford Industries purchases step-down electrical converters from two suppliers.The converters from the two suppliers appear to have the same average life (measured in hours) but the variability in useful life appears be different for the units provided by the two suppliers.In random samples of 8 converters from supplier A and 8 converters from supplier B, the standard deviation in sample A was 40 hours; the standard deviation in sample Bwas 55 hours.Assume that transformer life is normally distributed in each population..Test the null hypothesis that population variance B is no greater than the population variance A, against the alternative hypothesis that the population variance B is greater than the population variance A.Use a significance level of 5% for this one-tailed test and report your conclusion.

• A)Since F_stat is greater than F_c, we cannot reject the "B no greater than A" null hypothesis.
• B)Since F_stat is less than F_c, we can reject the "B no greater than A" null hypothesis.
• C)Since F_stat is greater than F_c, we can reject the "B no greater than A" null hypothesis.
• D)Since F_stat is less than F_c, we cannot reject the "B no greater than A" null hypothesis

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Definitions:

Memory Consolidation

The biochemical process(es) by which neural synaptic connections are strengthened or weakened.

Long-Term Memory

Long-term memory is the capacity to hold vast amounts of information, from facts to experiences and skills, for long periods, ranging from hours to a lifetime.

Anterograde Amnesia

A condition characterized by an inability to form new memories following the onset of the disorder, though recall of events prior may remain intact.

Hippocampus

A key region of the brain involved in the formation of new memories and associated with learning and emotions.