Respuesta :
Answer:
The lowest possible IQ scores of students remaining in the class is 84.46.
The highest possible IQ scores of students remaining in the class is 115.54.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Mean of 100 and a standard deviation of 15.
This means that [tex]\mu = 100, \sigma = 15[/tex]
Find the lowest and highest possible IQ scores of students remaining in the class.
Lowest:
The 15th percentile, which is X when Z has a pvalue of 0.15, so X when Z = -1.036.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-1.036 = \frac{X - 100}{15}[/tex]
[tex]X - 100 = -1.036*15[/tex]
[tex]X = 84.46[/tex]
Highest:
The 100 - 15 = 85th percentile, which is X when Z has a pvalue of 0.85, so X when Z = 1.036.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]1.036 = \frac{X - 100}{15}[/tex]
[tex]X - 100 = 1.036*15[/tex]
[tex]X = 115.54[/tex]
The lowest possible IQ scores of students remaining in the class is 84.46.
The highest possible IQ scores of students remaining in the class is 115.54.
