The variable x always equals 1
Answer:
We need a sample size of least 119
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Sample size needed
At least n, in which n is found when 
We don't know the proportion, so we use
, which is when we would need the largest sample size.






Rounding up
We need a sample size of least 119
If the two rectangles are similar than The answer is C. X=9.6
I am assuming you're doing a Punnet square, so you multiply each one. So on the top left box, it is -45x^2, the top right is 9x, bottom left is 35x, and bottom right is -7.
Make variables for each
L = library books
P = telephone books
T = text books
so.... L+P = 2T
now we have to fill in numbers