Respuesta :
Answer:
0.8315 = 83.15% probability that a randomly selected gas station in France charges more than $5.30 per gallon
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
The average price for a gallon of gasoline in France is $5.54. The standard deviation is $.25.
This means that [tex]\mu = 5.54, \sigma = 0.25[/tex]
What is the probability that a randomly selected gas station in France charges more than $5.30 per gallon?
This is 1 subtracted by the pvalue of Z when X = 5.30. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{5.3 - 5.54}{0.25}[/tex]
[tex]Z = -0.96[/tex]
[tex]Z = -0.96[/tex] has a pvalue of 0.1685
1 - 0.1685 = 0.8315
0.8315 = 83.15% probability that a randomly selected gas station in France charges more than $5.30 per gallon
