An Elementary School Principal Wants to Know the Mean Number

question 61

Multiple Choice

An elementary school principal wants to know the mean number of children in families whose
Children attend this school. He checks all the families using the school's registration records, and we
Create a 95% confidence interval based on a t-distribution. This procedure was not appropriate.
Why?

• A) At a given school families are not randomly selected.
• B) The population standard deviation is known, so he should have used a z-model.
• C) The entire population of families was gathered so there is no reason to do inference.
• D) Since these families are from only one school, the family sizes may be skewed.
• E) The recent record-setting family with twelve children is probably an outlier.

---

Definitions:

Competitive Buyer

A buyer in a market where numerous purchasers compete to acquire goods or services, often leading to more favorable prices.

Industry Supply Curve

A graphical representation that shows the relationship between the price of a good and the total output all firms in the industry are willing to produce.

Marginal Value

Additional benefit derived from purchasing one more unit of a good.

Consumer Surplus

The gap between the price consumers are ready to pay for a good or service and the price they actually incur.