2n^2-20=0
2n^2=20
n^2=20÷2
n^2=10
n=radical 10
Answer:
We need a sample size of at least 383.
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:
85% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
How large a sample would be required in order to estimate the fraction of tenth graders reading at or below the eighth grade level at the 85% confidence level with an error of at most 0.03
We need a sample size of at least n.
n is found with 
Then
Rounding up
We need a sample size of at least 383.
Step-by-step explanation:
slope = (y2 - y1)/(x2 - x1)
-4/3 = (6 - y)/[4-(-2)]
-4/3 = (6-y)/6
(-4/3)×6 = 6-y
-8 = 6-y
y = 6 + 8
= 14
So our equation to find this can be represented by 7x + 10 = 45.
(x representing miles run)
Just solve for x!
Subtract the 10 from both sides, you've got
7x = 35
And now to isolate the x, we divide both sides by 7.
Now we're left with just
x = 5!
We can check this by substituting 5 as x in our equation.
7x x 5 + 10 = 45
45 = 45
It's right!
So the runner ran 5 miles total.
Hope this helps!
If I skimmed over this too much, let me know and I'll try to explain the best that I can.
Answer: 11/12
Step-by-step explanation:
1. To solve this problem you can transform the mixed numbers given in the problem to fractions, as you can see below:
3 2/3=(3*3+2)/3=11/3
2 3/4=(4*2+3)/4=11/4
2. Now you must make the substraction of the fraction:
11/3-11/4=11/12
3. Therefore, the answer is 11/12
