TI 89 statistics topic index > TI-89 Graph Normal Distribution Curve
TI-89 Graph Normal Distribution Curve
The TI-89 graphing calculator can not only calculate z-scores and return values for normal distributions, it can graph the normal distribution curve as well. Graphing a normal distribution (a bell curve) can help you see what it is you are supposed to be looking for, and gives you one more tool in solving normal distribution problems. The TI-89 can graph a normal distribution curve with an area shaded for any value. For example, you could create a graph that is: less than a certain number, greater than a certain number, or in-between a certain set of numbers.
TI-89 Graph Normal Distribution Curve: Steps
Sample problem: Draw a normal distribution curve for student salaries during a typical semester. The student salaries have a mean (average) of $6,800 and standard deviation of $2,500. Shade the area on the graph that corresponds to salaries between $7,300 and $9,000.
Step 2: Press F2 3 and F2 4.
Step 3: Press F5 › 1.
Step 4: Scroll down and enter 7300 in the lower value box.
Step 5: Scroll down and enter 9000 in the upper value box.
Step 6: Scroll down and enter 6800 in the μ box.
Step 7: Scroll down and enter 2500 in the σ box.
Step 8: Scroll down. Turn Auto Scale to “yes” by pressing the right scroll key, then the down scroll key to select yes. Press Enter.
Tip: If you want to enter ∞ (infinity) as one of your lower or upper values, press the ♦ then Catalog.