On a given day, gasoline prices in the state of Colorado had a mean price of $2.

Question

On a given day, gasoline prices in the state of Colorado had a mean price of $2.28/gallon with a standard deviation of $0.09. A particular Colorado gas station had gasoline for $2.19/gallon Interpret the z-score for this gas station.

   The gas price of this station falls 9 standard deviations above the mean gas price of all Colorado stations.
       The gas price of this Colorado station falls 1 standard deviation below the mean gas price of all Colorado stations.
       The gas price of this station falls 8 standard deviations below the mean gas price of all Colorado stations.
       The gas price of this Colorado station falls 9 standard deviations below the mean gas price of all Colorado stations.

Explanation / Answer

z score is calculated as (x-mean)/s

thus here x=2.19, mean is 2.28 and s is 0.09

z=(2.19-2.28)/0.09=-1

therefore option B

Related Questions

Navigate

• Browse (All)
• Browse O
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.