Answer:
The answer is "0.6827".
Step-by-step explanation:
[tex]\bold{X \to N(\mu = 25, \sigma^2 = 16)}[/tex]
[tex]\to P(21 < X < 29) = P(\frac {21-25}{4} < \frac{X- \mu}{\sigma}< \frac{29-25}{4})[/tex]
[tex]= P(-1 < Z< 1)\\\\= P(Z> -1)-P(Z>1)\\\\= 1-P(Z< -1)-P(Z>1)\\\\= 1-P(Z> 1)-P(Z>1)\\\\= 1- 2 \times P(Z>1)\\\\=1-2 \times 0.15866 \\\\ = 1- 0.31732\\\\=0.6827[/tex]
