Answer :
Using the normal distribution, it is found that 2.28% of 1-month old girls will be categorized as having microcephaly.
Normal Probability Distribution
The z-score of a measure X of a normally distributed variable with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex] is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
The proportion more than two standard deviations below the mean is the p-value of Z = -2, given by 0.0228, hence 2.28% of 1-month old girls will be categorized as having microcephaly.
More can be learned about the normal distribution at https://brainly.com/question/4079902
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