Make an equation.
80% = 0.8
'of' is multiplication
'what number' is 'x'
'is' is an equal sign
0.8 * x = 64
0.8x = 64
Divide 0.8 to both sides:
x = 80
Honestly? Just review your notes and try to work out the problems yourself before taking a look at the answer. You can also google specific topics that the test will cover and try the practice problems.
Answer: 
.
Step-by-step explanation: We are given expression .
And expression is converted in 
.
Now, we need to transform the expression into a single exponent expression using the properties of exponents.
We know, according to the properties of exponents
Applying same rule in given expression, we get
On simplifying exponents, we would get t in exponent.
= .
Finding the sample size for estimating a population proportion.
The formula is:
n = (z/m)^2 p~(1−p~)
where:
Z is the z value of the confidence level where 95% is equal to 1.96
M is the margin of error where 0.05
And p~ is the estimated value of the proportion where it is 0.50
Solution:
n = (1.96/0.05)^2 (0.5) (1-0.5)
= 1.536.64 (0.5) (0.5)
= 768.32 (0.5)
= 384.16
This is the minimum sample size, therefore we should round it up to 385. The answer is letter c.
