Please help I feel like I am dying
1 answer:
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I hope this helps you
Answer:
c. 0.0142
Step-by-step explanation:
1) 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".
Let X the random variable that represent interest on this case, and for this case we know the distribution for X is given by:
And let represent the sample mean, the distribution for the sample mean is given by:
On this case
2) Solution to the problem
We want this probability:
The question on this case is ".Find the probability that the average price for 30 gas stations is less than $4.55". So then our value for n=30.
If we apply the formula for the z score to our probability we got this:
And using the normal standard table or the following excel code we calculate the probability "=NORM.DIST(-2.19,0,1,TRUE)"