Note this is for Confidence Intervals based on Z Scores only! You input your specifics into the green cells and don't touch anything else. You need to download before using.

1. Confidence Z-Score
Level Alpha Area to Left Z-Score (Rounded)
95% 0.050 0.975 1.959963985 1.96
93% 0.070 0.965 1.811910673 1.812
98% 0.020 0.99 2.326347874 2.326
99% 0.010 0.995 2.575829304 2.576
To find the Confidence Interval (like for Number 4 on Part 4 of the Lab), I built a little template based on the formulas they give
Enter Your Mean, Standard Deviation, number of data points, and Con
Mean Std Dev n (# of data pts) Desired Conf.
78.4 6.205 40 92%
Results (the true mean amount would be between these two values)
Calculation Cells, Do Not Change These Values
8% 0.96 1.750686071 1.751 1.717900224
Lower Upper
76.68 80.12
So you would say that with 92% confidence,
you can say the true mean is between 76.68 and 80.12
Note this if for Confidence Intervals based on Z Scores only! You input your specifics into the green cells and don't touch anyth

2. on the formulas they give you for the Z score on Part 3 of the Lab.
ONLY ENTER IN THE GREEN CELLS.
points, and Confidence Level TO FIND SOMETHING LIKE THE "LOWEST
POSSIBLE VALUE" YOU MIGHT CONSIDER
FINDING THE 98% OR 99% LOWER LIMIT.
WITH the 98% confidence lower limit you would
know that 99% of the time the actual would be
higher.
WITH the 99% confidence lower limit you would
know that 99.5% of the time the actual would be
higher.
cells and don't touch anything else.

3. GREEN CELLS.
G LIKE THE "LOWEST
OU MIGHT CONSIDER
R 99% LOWER LIMIT.
dence lower limit you would
e time the actual would be
dence lower limit you would
he time the actual would be