<span>Simplifying
49x^2 + -9 = 0
Reorder the terms:
-9 + 49x^2 = 0
Solving
-9 + 49x^2 = 0
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '9' to each side of the equation.
-9 + 9 + 49x^2 = 0 + 9
Combine like terms: -9 + 9 = 0
0 + 49x^2 = 0 + 9
49x^2 = 0 + 9
Combine like terms: 0 + 9 = 9
49x^2 = 9
Divide each side by '49'.
x^2 = 0.1836734694
Simplifying
x^2 = 0.1836734694
Take the square root of each side:
x = {-0.428571429, 0.428571429}
hope this helps!!</span>
Answer:
The 98% confidence interval estimate of the proportion of adults who use social media is (0.56, 0.6034).
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
.
Of the 2809 people who responded to survey, 1634 stated that they currently use social media.
This means that 
98% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
The lower limit of this interval is:

The upper limit of this interval is:

The 98% confidence interval estimate of the proportion of adults who use social media is (0.56, 0.6034).
4 sides. Think of a trapezoid like a drunk rectangle.
-Hope this helps!