The Average Time Before Breakdown of a Machine Is Normally

question 25

Multiple Choice

The average time before breakdown of a machine is normally distributed and has a mean of 18 weeks and a standard deviation of three weeks. If breakdown cost averages $2,000 and preventive maintenance costs $1,400, what is the optimal preventive maintenance interval?

• A)16.4 weeks
• B)14.6 weeks
• C)16.9 weeks
• D)19.6 weeks
• E)21.3 weeks

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Definitions:

Endoplasmic Reticulum

A network of membranous tubules within the cytoplasm of eukaryotic cells, involved in protein and lipid synthesis, and calcium storage.

Ribosomes

Cellular organelles that function as the site of protein synthesis, reading mRNA and assembling amino acids into proteins.

Golgi Apparatus

A cell organelle involved in modifying, sorting, and packaging proteins and lipids for secretion or use within the cell.

Vacuole

Membrane-bound sac, larger than a vesicle; usually functions in storage and can contain a variety of substances. In plants, the central vacuole fills much of the interior of the cell.