The price of an item has dropped to 77$ today. Yersterday it was 140$. Find the percentage decrease.
1 answer:
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Answer:
So the best answer for this case would be:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the costs of unleaded gasoline of a population, and for this case we know the distribution for X is given by:
Where and
We select a sample size of n =16. Since the distribution for X is normal then we know that the distribution for the sample mean is given by:
So the best answer for this case would be:
Α * R = L where L is the length of the arc of the circle, R is the radius of the circle, and α is the central angle <span>measured </span>in radians, so:
