Answer:
The 95% confidence interval is 
Step-by-step explanation:
From the question we are told that
The sample mean difference is 
The standard error is SE = 0.03
Given that the confidence interval is 95% then the level of significance is mathematically evaluated as



Next we obtain the critical value of
from the normal distribution table, the value is 
Generally the margin of error is mathematically represented as

substituting values


The 95% confidence interval is mathematically represented as

substituting values


Y=7x+3 because slope intercept form is y=mx+b where x is the slope and b is the y intercept so when you plug in the slope of 7 and the y intercept of 3 you get the equation y=7x+3.
Well where is the functions?