SOLUTION: 1)A weight-loss clinic guarantees that its new customers will lose at least 5 lb by the end of their first month of participation or their money will be refunded. If the loss of we

Question 136827: 1)A weight-loss clinic guarantees that its new customers will lose at least 5 lb by the end of their first month of participation or their money will be refunded. If the loss of weight of customers at the end of their first month is normally distributed, with a mean of 6.8 lb and a standard deviation of 0.81 lb, find the percent of customers who will be able to claim a refund.

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Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A weight-loss clinic guarantees that its new customers will lose at least 5 lb by the end of their first month of participation or their money will be refunded. If the loss of weight of customers at the end of their first month is normally distributed, with a mean of 6.8 lb and a standard deviation of 0.81 lb, find the percent of customers who will be able to claim a refund.
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Draw a normal curve; put 6.8 lb on the horizontal axis in the middle
Put a point where you think 5 lb would be.
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Find the z-value of that "5" point:
z(5) = (5-6.8)/0.81 = -2.222222...
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Use your calculator or z-chart to find the % of population
to the left of z--2.22222..
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Use normalcdf(-10,-2.2222) to get 0.013134...
Conclusion: About 1.3%of the customers will be able to claim a refund.
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Cheers,
Stan H.

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