14 is 30% of what number?
1 answer:
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Answer:
4 + (or -) 3i
Step-by-step explanation:
Hi!
Alright, so we're going to move all of the variables and constants to one side. Then, using the quadratic formula, we'll find the answer.
1. Move 12x-5 to the left side of the equation by
a. Subtracting 12x from both sides
b. adding 5 to both sides.
1: x^2+4x+20-12x+5
2. Group the common terms
x^2+4x-12x+20+5 --> x^2-8x+25
3. Look at the problem. We can't factor this.
Explanation for why this isn't factorable (you can skip this)
(1) 25 is positive, so its two factors will both be either positive or negative. We're looking for a negative 8, so let's go with negative.
(2) Factors of 25: 1 & 25, 5 &5
Seeing the problem? Ya, none of the factors of 25 sum to eight. So, instead, we're going to use the quadratic formula.
4. So, the quadratic formula:
Our equation is x^2-8x+25=0
a is the constant in front of the x^2
b is the constant in front of the x
c is the term without any x values
so, a=1, b=-8, and c= 25
Into equation:
=
=
8/2 = 4
sqrt(-36) = 6i
6i/2 = 3i (remember, we still have the two in the denominator)
4 + (or -) 3i
Answer:
The margin of error for her confdence interval is of 0.3757.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 18 - 1 = 17
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 17 degrees of freedom(y-axis) and a confidence level of . So we have T = 2.8982
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
Standard deviation of 0.55 meters.
This means that
What is the margin of error for her 99% confidence interval?
The margin of error for her confdence interval is of 0.3757.