Let x be the number of students in the class the
the number of students in the class when 1 in 4 are absent = x - 0.25x = 0.75x
After Jen returns there are x - 0.2x = 0.80x so we have the equation
0.75x + 1 = 0.80x
0.05x = 1
x = 1 / 0.05 = 20 Answer
So there are 20 students in the class.
No. students not here today = 0.80 * 20 = 16 Answer
Answer: C
Step-by-step explanation:
Answer:
The margin of error is of 0.01.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Z-table as such z has a p-value of
.
That is z with a pvalue of
, so Z = 1.037.
The margin of error is of:

In which
is the standard deviation of the population and n is the size of the sample.
Standard deviation was 0.21.
This means that 
Sample of 450:
This means that 
What is the margin of error, assuming a 70% confidence level, to the nearest hundredth?



The margin of error is of 0.01.