HP 33s - Manual (Page 269)

Statistics Programs 16–9
Example 1:
Fit a straight line to the data below. Make an intentional error when keying in the
third data pair and correct it with the undo routine. Also, estimate y for an x value
of 37. Estimate x for a y value of 101.
X 40.5 38.6 37.9 36.2 35.1 34.6
Y 104.5 102 100 97.5 95.5 94
Keys:
(In RPN mode)
Display: Description:
X S %@
)
 Starts straight–line routine.
40.5 g
&@
value Enters x–value of data pair.
104.5 g
%@
)
 Enters y–value of data pair.
38.6 g
&@

)
 Enters x–value of data pair.
102 g
%@
)
 Enters y–value of data pair.
Now intentionally enter 379 instead of 37.9 so that you can see how to correct
incorrect entries.
Keys:
(In RPN mode)
Display: Description:
379 g
&@

)
 Enters wrong x–value of data
pair.
g
%@
)
 Retrieves %@ prompt.
X U %@
)
 Deletes the last pair. Now
proceed with the correct data
entry.
37.9 g
&@

)
 Enters correct x–value of data
pair.