If I've read this correctly, it looks like this.

If that is correct, then the first step is to put the top part of the denominator over 3x
The next part is to flip a three tier fraction. I'm afraid I have to show what happens. My latex is not that strong.
What you get is

This is just about your final answer. You could write it as

Answer:
The student who weighted the rock 5 times has a 95% confidence interval of (25.2, 29.1) which is guaranteed to be more wider (less precise) than the other student who weighted the rock 20 times.
Step-by-step explanation:
What is Confidence Interval?
The confidence interval represents an interval that we can guarantee that the target variable will be within this interval for a given confidence level.
The confidence interval is given by

Where
is the mean weight
is the standard deviation
is the critical value from t-table and n is the sample size.
The term
is known as margin of error.
As the sample size is decreased the corresponding margin of error increases which results in wider confidence interval which means smaller precision.
The student who weighted the rock 5 times has a 95% confidence interval of (25.2, 29.1) which is guaranteed to be more wider (less precise) than the other student who weighted the rock 20 times.
We can say with 95% confidence that the true mean weight of the rock is within the interval of (25.2, 29.1).
Yes. Because blah blah blas blah blah blah
XD
Answer:
if 1cm is for 1km there are 12km
Step-by-step explanation:
it can depend on the size of the map but if there is a scale which shows how many km per cm then multiply by 12