Casio ALGEBRA FX2.0 Advanced Statistics Examples 1 - Manual (Page 7)

7
examples
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Example A team of eye surgeons has developed a new technique for a risky eye
operation to restore the sight of people blinded from a certain disease.
Under the old method it is known that only 30% of the patients who
undergo this operation recover their eyesight. Suppose that surgeons
in various hospitals have performed a total of 250 operations using
the new method and that 93 have been successful (the patients fully
recovered their sight). Can we justify the claim that the new method is
better than the old one?(Use a 1% level of significance.)
Procedure
1 m STAT2
2 3 (TEST) b (Z) d (1-Prop)
3 3 (>) c
.d w
jd w
cfa w
1 (None) c
4 1 (CALC)
6 (DRAW)
Result Screen
Since P = 6.4915e-3 < 0.01 (level of significance), we can reject the null hypothesis that the
successful probability of new operation is 0.3 and conclude that it can be said the new
method obtains good results more than existing method. That is to say it is more effective by
new methods.