Answer:
C
Step-by-step explanation:
Answer:
x = 1, y = 6
Step-by-step explanation:
y = 6x
2x + 3y = 20
Plug y as 6x in the second equation and solve for x.
2x + 3(6x) = 20
2x + 18x = 20
20x = 20

x = 1
Plug x as 1 in the first equation and solve for y.
y = 6(1)
y = 6
The <em>trigonometric</em> expression
is equivalent to the <em>trigonometric</em> expression
.
<h3>How to prove a trigonometric equivalence</h3>
In this problem we must prove that <em>one</em> side of the equality is equal to the expression of the <em>other</em> side, requiring the use of <em>algebraic</em> and <em>trigonometric</em> properties. Now we proceed to present the corresponding procedure:












The <em>trigonometric</em> expression
is equivalent to the <em>trigonometric</em> expression
.
To learn more on trigonometric expressions: brainly.com/question/10083069
#SPJ1
Answer:
A sample size of 392 is required.
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:

18% of students struggle in their classes because they don't spend more than 8 hours studying independently outside of a 4-unit class.
This means that 
99% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
You would like to be 99% confident that your estimate is within 5% of the true population proportion. How large of a sample size is required?
A sample size of n is required.
n is found when M = 0.05. So






Rounding up:
A sample size of 392 is required.
50 students preferred science...
Explanation:
we can consider the numbers 5 and 4 in the ratio as units
now we need to know how much each unit represent
units = 5 + 4 = 9
my sample = 90 students
each unit = 90/9 = 10 students
so each unit represents 10 students
back to the ratio
who preferred science = 5
who preferred English = 4
Number of students choose Science = 5 * 10 = 50