Answer:
They can either decrease the confidence level or increase the sample size, that is, survey more students.
Step-by-step explanation:
The width of a confidence interval is given by:

In which z is the critical value correponding to the confidence level(higher confidence level, higher z is),
is the standard deviation of the population and n is the size of the sample.
The students realize that this interval contains a large margin of error. What can they do to make a narrower interval?
Looking at the formula for M, they can either decrease the confidence level or increase the sample size, that is, survey more students.
Answer:


Step-by-step explanation:
Given
See attachment for MNPQ and RSTU
Required
Find x and y
To solve this question, we make use of equivalent ratios of corresponding side lengths.
The ratio of corresponding sides are:




From the attachment, we have:



To solve for x, we equate
and 

Express as fraction

Make x the subject




To solve for y, we equate
and 

Express as fraction

Make y the subject




So first create and define your variables:
Z = amount of zebra fish
N = amount of neon tetras
Now create your equations:
2z+2.15n=31.20
z+n=15
This is your system. There are multiple methods to use but in this problem I’ll use the substitution method by simplifying the bottom equation.
2z+2.15n=31.20
z=15-n
Now I’ll plug the bottom equation into the top one.
2(15-n)+2.15n=31.20
And just solve from here.
30-2n+2.15n=31.20
0.15n=1.20
n=8
So he bout 8 neon tetras, and 15-8= 7, so he bought 7 zebra fish
Answer:
Step-by-step explanation:
remeber is (x,y) so it will be like this 
nice
i think there's supposed to be more to the problem lol