Answer:
Solution: C) 7.815
Hint: From Chi-square table with (k-r-1)=(6-2-1) = 3 d.f the critical value = 7.8147
Rewrite it in the form a^2 - b^2, where a = 2x and b = 5
(2x)^2 - 5^2
Use the Difference o Squares: a^2 - b^2 = (a + b)(a - b)
<u>(2x + 5)(2x - 5) </u>
Its 81 centimeters because you round 5 and over. So nearest centimeter means 2 whole numbers which is 81
The decimal number used to represent 5 out of 100 missed on her test is 0.95.