Fifteen SmartCars Were Randomly Selected and the Highway Mileage of Each

question 55

Short Answer

Fifteen SmartCars were randomly selected and the highway mileage of each was noted. The analysis yielded a mean of 47 miles per gallon and a standard deviation of 5 miles per gallon. Which of the following would represent a 90% confidence interval for the average highway mileage of all SmartCars? A) $47 \pm 1.761 \frac { 5 } { \sqrt { 15 } }$

B) $47 \pm 1.345 \frac { 5 } { \sqrt { 15 } }$

C) $47 \pm 1.753 \frac { 5 } { \sqrt { 15 } }$

D) $47 \pm 1.645 \frac { 5 } { \sqrt { 15 } }$

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Definitions:

Random Assignment

Refers to the process in procedural statistics and experimental design where study participants are assigned to either the treatment or control group using a random method to ensure that each participant has an equal chance of being placed in any group.

External Validity

The extent to which the findings from a study can be generalized to other people, other settings, and other time periods.

Placebo

An inactive substance or treatment given to a participant in a study, used to test the efficacy of a therapy or medication.

Accomplices

Individuals who actively assist, facilitate, or encourage another person in the commission of a crime, without necessarily taking part in the actual criminal act.