Respuesta :
Answer:
d. -1.9; not unusual
Step-by-step explanation:
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 problem, we have that;
[tex]X = 50, \mu = 69, \sigma = 10[/tex].
So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{50 - 69}{10}[/tex]
[tex]Z = -1.9[/tex]
A z-score of -1.9 is higher than -2 and lower than 2, so it is not unusual.
So the correct answer is:
d. -1.9; not unusual
