A Grocery Store Is Interested in Determining Whether or Not $90 \%$

question 16

Multiple Choice

A grocery store is interested in determining whether or not a difference exists between the shelf life of Tasty Choice doughnuts and Sugar Twist doughnuts. A random sample of 100 boxes of each brand was selected and the mean shelf life in days was determined for each brand. A $90 \%$ confidence interval for the difference of the means, $\mu _ { T C } - \mu _ { S T }$ , was determined to be $( 1.3,2.5 )$ .

• A) We know that \(90 \%\) of Tasty Choice doughnuts last between \(1.3\) and \(2.5\) days longer than Sugar Twist doughnuts.
• B) Based on this sample, we are \(90 \%\) confident that Sugar Twist doughnuts will last on average between \(1.3\) and \(2.5\) days longer than Tasty Choice doughnuts.
• C) We are \(90 \%\) confident that a randomly selected box of Tasty Choice doughnuts will have a shelf life that is between \(1.3\) and \(2.5\) days longer than a randomly selected box of Sugar Twist doughnuts.
• D) We know that \(90 \%\) of all random samples done on the population will show that the mean shelf life of Tasty Choice doughnuts is between \(1.3\) and \(2.5\) days longer than the mean shelf life of Sugar Twist doughnuts.
• E) Based on this sample, we are \(90 \%\) confident that Tasty Choice doughnuts will last on average between \(1.3\) and \(2.5\) days longer than Sugar Twist doughnuts.

---

Definitions:

Supply

The total amount of a good or service that is available for purchase at various prices in a given market.

Japanese Yen

The official currency of Japan, used as a medium of exchange and a standard of value within the country.

Upsloping

Describes a curve or line on a graph that shows an increase in value or quantity as it moves from left to right.

Flexible Exchange Market

Refers to a foreign exchange market where exchange rates are allowed to move due to market forces without intervention by country governments.