Answer:
To find part A you need to find common denominator.
1/3 + 3/5=
5/15 + 9/15= 14/15
His mistake for a is that he didn't find the common denominator and that he just added the fraction as it is. So the corrected version would be 14/15.
To find part B you also need to find the least common denominator.
11/12-5/6=
11/12-10/12=1/12
His mistake was that he didn't find the least common denominator and he subtracted the fraction as it is. The answer corrected would be 1/12.
Step-by-step explanation:
Answer: The standard error of the mean = 0.5
Step-by-step explanation:
Given : Sample size : n = 144
Standard deviation : 
The formula to find the standard error of the mean is given by :-
i.e. 
Hence, the standard error of the mean =0.5
5^2(2-sqrt3) is the answer here is the link to how to do it https://socratic.org/questions/suppose-an-isosceles-triangle-abc-has-a-30-and-b-c-5-what-is-the-leng...
