The Mean Length of a Candy Bar Is 43 Millimeters

question 58

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:

Tertiary Structure

The three-dimensional shape of a protein molecule formed by bends and folds of its polypeptide chain.

Sulfhydryl

A functional group with the structure R-SH, where R is an organic alkyl or aryl group and SH denotes a sulfur atom bonded to a hydrogen atom, important in protein structure.

α-Helix

An α-Helix is a common motif in the secondary structure of proteins, characterized by a right-handed coil with each amino acid residue linked by hydrogen bonds.

Fibrous Protein

Proteins with a long, filamentous shape, such as collagen or keratin, which provide structural support for cells and tissues.