A Carload of Steel Rods Has Arrived at Cybermatic Construction

question 28

Multiple Choice

A carload of steel rods has arrived at Cybermatic Construction Company. The car contains 50,000 rods. Claude Ong, manager of Quality Assurance, directs his crew measure the lengths of 100 randomly selected rods. If the population of rods have a mean length of 120 cm and a standard deviation of 0.05 cm, the probability that Claude's sample has a mean less than 119.985 cm is ___.

• A) 0.9974
• B) 0.0026
• C) 0.4987
• D) 0.0013
• E) 0.0030

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Definitions:

Groups

Groups refer to sets of subjects or items that are categorized together based on specific characteristics or treatments in an experiment or study.

Statistical Analysis

The process of collecting, reviewing, interpreting, and presenting data to discover underlying patterns and trends.

P < .01

Indicates that the probability of the observed data (or more extreme) given that the null hypothesis is true is less than 1%, suggesting strong evidence against the null hypothesis.

Null Hypothesis

A presumption in statistical inference that indicates no significant variance between groups or no significant relationship between variables.