HP F2226A - 48GII Graphic Calculator User Manual page 625

Example 1 -- For the following (x,y) data, determine the 95% confidence
interval for the slope B and the intercept A
x
y
Enter the (x,y) data in columns 1 and 2 of ΣDAT, respectively. A scatterplot of
the data shows a good linear trend:
option in the ‚Ù menu, to get:
Use the Fit Data..
3: '-.86 + 3.24*X'
2: Correlation: 0.989720229749
1: Covariance: 2.025
These results are interpreted as a = -0.86, b = 3.24, r
and s = 2.025. The correlation coefficient is close enough to 1.0 to confirm
xy
the linear trend observed in the graph.
Single-var...
From the
0.790569415042,y = 8.86, s
Next, with n = 5, calculate
S ( n ) 1
xx
5 1
. 2
5 2
2.0 2.5 3.0 3.5
5.5 7.2 9.4 10.0
option of the ‚Ù menu we find: x = 3, s
= 2.58804945857.
y
2
s 5 ( ) 1 . 0 7905694150
x
n 1
2 2
s s 1 ( r
e y
n 2
2
5880 ... 1 ( . 0 9897 ...
4.0
12.2
= 0.989720229749,
xy
2
42 2 5 .
2
)
xy
2
) . 0 1826 ...
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=
x