Answer:
x = 8 cm
Step-by-step explanation:
The first step in solving this problem is to determine which trig function applies. The diagram shows that this triangle is a right triangle, that side x is opposite the 25-degree angle, and that the hypotenuse has a length of 18 cm.
The sine function of an angle Ф is defined as the ratio of the opposite side to the hypotenuse. In this case, sin Ф (or sin 25 degrees) equals x/(18 cm).
We need to determine the value of x. Adapt the above equation to this particular situation: sin 25 degrees = x/(18 cm).
To solve for x, multiply both sides of the most recent equation, above, by (18 cm). The following results: (18 cm)(sin 25 degrees) = x.
Next, use a calculator to find the value of sin 25 degrees: It is 0.4226.
Then the desired value of x is (18 cm)(0.4226), or x = 7.61 cm. This should be rounded off to x = 8 cm to reflect the level of accuracy of the given 18 cm.
Answer:
The 85% confidence interval for the population proportion of tenth graders reading at or below the eighth grade level is (0.259, 0.301).
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
.
For this problem, we have that:
972 students, 700 read above the eight grade level. We want the confidence interver for the proportion of those who read at or below the 8th grade level. 972 - 700 = 272, so 
85% 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 85% confidence interval for the population proportion of tenth graders reading at or below the eighth grade level is (0.259, 0.301).
Answer:
Impossible, not enough to answer the question
Step-by-step explanation:
As you can see because there is no number or variable past the equal sign it is simply an expression, please correct me if I am wrong but even if the other side was 0, I doubt a teacher would give this problem with decimals, but it may just be me.
Answer:
Step-by-step explanation:
If a given variable varies inversely with another variable, an increase in the value of the given variable would cause a corresponding decrease in the value of the other variable. Also, a decrease in the value of the given variable would cause a corresponding increase in the value of the other variable.
If y varies inversely with x, we would introduce a cost of variation, k so that the expression becomes
y = k/x
When y = 0.25, x = 8
Substituting into the expression above, it becomes
0.25 = k/8
k = 0.25 × 8
k = 2
The inverse variation function is
y = 2/x