Answer:
P (34<X<39) = 0.5899
Step-by-step explanation:
When the distribution is normal, we use the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
[tex]\mu = 37, \sigma = 3[/tex]
What is the probability that a cat would return to it's dish between 34 and 39 times a day.
This is the pvalue of Z when X = 39 subtracted by the pvalue of Z when X = 34. So
X = 39
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{39 - 37}{3}[/tex]
[tex]Z = 0.67[/tex]
[tex]Z = 0.67[/tex] has a pvalue of 0.7486
X = 34
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{34 - 37}{3}[/tex]
[tex]Z = -1[/tex]
[tex]Z = -1[/tex] has a pvalue of 0.1587
0.7486 - 0.1587 = 0.5899
So
P (34<X<39) = 0.5899
