Answer:
The lower limit is 75.04
The upper limit is 78.96
Step-by-step explanation:
From the question we are told that
The sample size is 
The sample mean is 
The standard deviation is 
Given that the confidence level is 95% then the level of significance is mathematically represented as


The critical value for
obtained from the normal distribution table is

Generally the margin of error is mathematically represented as

=> 
=> 
The 95% confidence interval is mathematically represented as

=> 
=> 
Answer:
y=[x+1]-3 because it's at the end of the line
You just have to write it down (7.7.7.7.7.7.7=49)
Both are correct they just chose a different variable to solve for first. they will both get correct answers if they do the rest correctly.
Answer: 9 i think, i don't know hope i helped :)