Respuesta :
Answer:
71.57% of student heights are lower than Darnell's height
Step-by-step explanation:
Problems of normally distributed samples are solved using 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 = 150, \sigma = 20[/tex]
Darnell has a height of 161.4 centimeters. What proportion of student heights are lower than Darnell's height?
This is the pvalue of Z when X = 161.4.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{161.4 - 150}{20}[/tex]
[tex]Z = 0.57[/tex]
[tex]Z = 0.57[/tex] has a pvalue of 0.7157
71.57% of student heights are lower than Darnell's height
Answer:
0.7157
Step-by-step explanation:
Darnell's height is 161.4 - 150 = \goldD{11.4}161.4−150=11.4161, point, 4, minus, 150, equals, start color #e07d10, 11, point, 4, end color #e07d10 relative to the mean.
This is \dfrac{\goldD{11.4}}{20} = \blueD{0.57}
20
11.4
=0.57start fraction, start color #e07d10, 11, point, 4, end color #e07d10, divided by, 20, end fraction, equals, start color #11accd, 0, point, 57, end color #11accd standard deviations relative to the mean. This is Darnell's z-score.
Hint #22 / 4
We want to find the proportion of student heights below a z-score of \blueD{0.57}0.57start color #11accd, 0, point, 57, end color #11accd:
