Agrocery stores studies how long it takes customers to get through the speed check lane. they assume that if it takes more than 10 minutes, the customer will be upset. find the probability that a randomly selected customer takes more than 10 minutes if the average is 8.56 minutes with a standard deviation of 1.04 minutes.

The probability that a randomly selected customer takes more than 10 minutes will be 8.38%

Explanation

The average or mean is 8.56 minutes and standard deviation is 1.04 minutes.

Formula for finding the z-score is:  

So, the z-score for 10 minutes will be.....

Now, according to the standard normal distribution table,   . So.....

So, the probability that a randomly selected customer takes more than 10 minutes will be 8.38%

let x be the money she spent so that she can earn the free t-shirt.

since, she already spent $112.49

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also, as per the statement: jennifer must spend $250 or more in order to qualify for a free t-shirt at the store.

then,

we have an inequality i.,e

subtract 112.49 from both sides we get;

therefore, $137. 51 more money does jennifer need to spend so that she can earn the free t-shirt