Investigators Gave Caffeine to Fruit Flies to See If It

question 22

Multiple Choice

Investigators gave caffeine to fruit flies to see if it affected their rest. The four treatments were a control, a low caffeine dose of 1 mg/ml of blood, a medium dose of 3 mg/ml of blood, and a higher caffeine dose of 5 mg/ml of blood. Twelve fruit flies were assigned at random to the four treatments, three to each treatment, and the minutes of rest measured over a 24-hour period were recorded. Assume the data that follow are four independent SRSs (one from each of the four populations of caffeine levels) and that the distribution of the yields is Normal. A partial ANOVA table produced by Minitab follows, along with the means and standard deviation of the yields for the four groups. The conclusion that you would draw from this test is:

• A)accept the null hypothesis; all of the groups have the same mean.
• B)fail to reject the null hypothesis; there is no evidence to suggest that the groups have different means.
• C)reject the null hypothesis; all of the group means are different.
• D)reject the null hypothesis; at least one of the groups has a mean that is different.

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Definitions:

Arterial Walls

The layers of tissue that form the outer structure of arteries, responsible for maintaining blood pressure and flow throughout the body.

Heart Contracts

The process by which the heart muscle actively tightens and relaxes to pump blood throughout the body.

Orthostatic Hypotension

A form of low blood pressure that happens when standing up from sitting or lying down, causing dizziness or lightheadedness.

Blood Pressure

The pressure exerted by circulating blood upon the walls of blood vessels, a critical indicator of cardiovascular health.