Answer:
The probability that X is between 1.48 and 15.56 is
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
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 pvalue, we get the probability that the value of the measure is greater than X.
X is a normally distributed random variable with a mean of 8 and a standard deviation of 4.
This means that
The probability that X is between 1.48 and 15.56
This is the pvalue of Z when X = 15.56 subtracted by the pvalue of Z when X = 1.48. So
X = 15.56
has a pvalue of 0.9706
X = 1.48
has a pvalue of 0.0516
0.9706 - 0.0516 = 0.919
Write out the probability notation for this question.
The probability that X is between 1.48 and 15.56 is