Perform the indicated operation. 3 and 6/7 divided by 1/7 equals to as a whole number

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

Line l passes through points (0,4) and (3,6) what is the slope of a line that is parallel to line l -2/3 -3/2 2/3 3/2

Yesterday i ran 5 miles. today, i ran 3.7 miles. did my percent increase, decrease or is it a percent error? plz i need