Get insightful responses to your questions quickly and easily on IDNLearn.com. Discover detailed and accurate answers to your questions from our knowledgeable and dedicated community members.

According to psychologists, IQs are normally distributed, with a mean of 100 and a standard deviation of 18.a. What percentage of the population has IQs between 82 and 100?

Sagot :

To solve this question, we will have to find the Z score.

[tex]Z=\frac{x-\bar{x}}{s.d}[/tex]

Where x is the value of the IQ

X-bar is the mean.

s.d is the standard deviation

[tex]\begin{gathered} Z_1=\frac{82-100}{18} \\ =-\frac{18}{18} \\ =-1 \end{gathered}[/tex][tex]Z_2=\frac{100-100}{18}[/tex][tex]\begin{gathered} Z_2=\frac{0}{18} \\ =0 \end{gathered}[/tex]

The percentage of the population with IQs between 82 and 100 will be calculated thus:

[tex]\begin{gathered} P(-1-1) \\ =0.5-0.1587 \\ =0.34134 \\ \text{The percentage is}\colon \\ =0.34134\times100=34.134\text{ \%} \end{gathered}[/tex]