A Study of Nickels Showed That the The Standard Deviation

question 23

Multiple Choice

A study of nickels showed that the the standard deviation of the weight of nickels is 150 milligrams. A coin counter manufacturer wishes to find the 80% confidence interval for the average weight of a nickel. How many nickels does he need to weigh to obtain an average accurate to within 10 milligrams?

• A) 225
• B) 369
• C) 613
• D) 159

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Definitions:

Lateral Roots

Roots that branch off from the main root to increase the plant's ability to absorb water and nutrients from the soil.

Cortex

In biology, the outer layer of an organ or structure, such as the cerebral cortex of the brain or the cortex of a plant root or stem.

Symplast

The network of cytoplasm of multiple plant cells connected by plasmodesmata, facilitating intercellular communication.

Cytoplasm

The jelly-like substance within a cell that contains the cytosol, organelles, and inclusions, exclusive of the nucleus.