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Statistical Probabilities and Distributions
Homework for Prob./Dist. Lesson 14
- Suppose you remember the triangular numbers, but can't
remember their formula. Enter the following values into
L1: 1, 2, 3 and L2: 1, 3, 6.
Now do a QuadReg L1,L2
using your TI-83+ calculator (STAT, CALC, 5)
and interpret the results (rewrite the formula in standard form).
- Suppose further you really couldn't remember if the relationship
was quadratic. Try a CubicReg L1,L2
and interpret the results.
- Add an additional point onto the end of
L1: 4 and L2: 10.
Repreform the CubicReg L1,L2
and interpret the results.
-
Try the CubicReg L1,L2
with L1: 1, 2, 3, 4 and L2: 1, 5, 14, 30
(sums of squares) and interpret the results.
Try to express your answer in an aesthetically pleasing form
(i.e. fractions not decimal fractions).
- Question one can be done by solving three equations in
three unknowns. Specifically, let
ax2 + bx +c = y.
Then substitute each value of x and equate it to the corresponding
y value. Solve these three equations manually
by elimination (due to the regular spacing first c, then b
eliminate easily).
- Solve the above equations using your calculator, either using
augmented or inverse matrices. Record the pertinent keystrokes here.