Answer:
A sample of 1077 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 of:

42% of freshmen do not visit their counselors regularly.
This means that 
98% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
How large of a sample size is required?
A sample size of n is required, and n is found when M = 0.035. So






Rounding up:
A sample of 1077 is required.
Answer:
x+3y=-9
Step-by-step explanation:
-2(x+3y)=18
x+3y=18/-2
x+3y=-9
Answer:
P(t) = 27000 * (1/9)^(t/4)
Step-by-step explanation:
This problem can me modelled with an exponencial formula:
P = Po * (1+r)^t
Where P is the final value, Po is the inicial value, r is the rate and t is the amount of time.
In this problem, we have that the inicial population/value is 27000, the rate is -8/9 (negative because the population decays), and the time t is in months, so as the rate is for every 4 months, we use the value (t/4) in the exponencial.
So, our function will be:
P(t) = 27000 * (1-8/9)^(t/4)
P(t) = 27000 * (1/9)^(t/4)
Answer:
(x²-2x)/(2x+6)
Step-by-step explanation:
When you are asked to divide two fractions just do keep-change-flip. Keep the first fraction, change the ÷ to x and flip the second fraction upside down. So the problem becomes ((x-2)/(x+3)) times (x/2). Then just multiply numerators and multiply denominators.
I think this is what you mean.
(5 + 2) + 6 = 7 + 6 = 13
5 + (2 + 6) = 5 + 8 = 13
I hope this helps. :)