13. In a survey involving all PVCC students, it was found that \( 30 \% \) of them exercise regularly. (a) 4 pts If 20 PVCC students are randomly selected, find the probability that exactly 5 of them exercise regularly. Round to 4 decimal places. (b) 4 pts] If 20 PVCC students are randomly selected, find the probability that more than 6 of them exercise regularly. Round to 4 decimal places.

(c) (i) Given that \( \sqrt{2} \) is irrational, show that \( \sqrt{2}+3 \) is irrational. (ii) Express \( 0.0 \overline{810} \) as a fraction in the form \( \frac{p}{q} \), where \( p \) and \( q \) are integers.

7) \( 1 \frac{1}{2} \) cups of sugar for every \( \frac{2}{3} \) cup of flour

Sketch the graphs of \( y=e^{x}, y=e^{-x}, y= \) \( e^{x+2} \), and \( y=e^{x}+2 \) on the same coordinate plane?

4 Welche der Wurzeln sind ganzzahlige Vielfache von \( \sqrt{2}, \sqrt{3} \) oder \( \sqrt{5} \) ? \( \sqrt{20} ; \quad \sqrt{125} ; \quad \sqrt{72} ; \quad \sqrt{147} ; \sqrt{128} ; \quad \sqrt{242} ; \quad \sqrt{300} ; \sqrt{722} ; \sqrt{800} \)

What is the formula for margin of error for estimating \( \mu \) with a confidence interval? \( z \times d \sqrt{n} \) \( \alpha \sqrt{n} \) \( z \times 1 / \sqrt{n} \)