The Mean Length of a Candy Bar Is 43 Millimeters

question 52

Multiple Choice

The mean length of a candy bar is 43 millimeters. There is concern that the settings of the machine cutting the bars have changed. Test the claim at the 0.02 level that there has been no change in the mean length. The alternate hypothesis is that there has been a change. Twelve bars (n = 12) were selected at random and their lengths recorded. The lengths are (in millimeters) 42, 39, 42, 45, 43, 40, 39, 41, 40, 42, 43, and 42. The mean of the sample is 41.5 and the standard deviation is 1.784. Computed t = -2.913. Has there been a statistically significant change in the mean length of the bars?

• A) Yes, because the computed t lies in the rejection region.
• B) No, because the information given is not complete.
• C) No, because the computed t lies in the area to the right of -2.718.
• D) Yes, because 43 is greater than 41.5.

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Definitions:

Conditional Positive Regard

An attitude of acceptance and respect on the condition that one behaves in a certain way, often discussed in the context of humanistic psychology.

Positive Self-talk

The practice of making affirming and encouraging statements to oneself, which can influence one's attitude, behavior, and emotional state in a positive way.

Self-talk Benefits

Positive effects arising from the practice of intentionally generating affirmative inner dialogue, such as improved mood, reduced stress, and enhanced performance.

Self-image

The mental portrayal, concept, or image an individual holds about themselves.