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Manuals/calci/CHITEST (view source)
Revision as of 04:47, 26 November 2013
, 04:47, 26 November 2013→Examples
==Examples==
==Examples==
A student investigated the chance of getting viral fever for a period of a school that took vitamin tablets every day.
A student investigated whether taking vitamin tablets every day for a school term affected peoples chances of getting a Viral fever during the period. The total number of students 880. In that 639 students didn't get viral fever and 241 students got fever .But the expected ratio is 1:3.
'''Answer''':
If the ratio is 1:3 and the total number of observed individuals is 880, then the expected numerical values should be 660 didn't get and 220 students will get that fever.
Didn't get fever Get fever
observed 639 241
values
Expected
values 660 220
{| id="TABLE3" class="SpreadSheet blue"
|- class="even"
!
! No Fever
! Get Fever
|- class="odd"
!Observed Values
| 639
| 241
|- class="even"
! Expected Values
| 660
| 220
|}
(oi-ei)^2/ei 0.668 2
The x^2 value is 2.668
Now df=(r-1)(c-1)=(2-1)(2-1)=1
From the chisquared distribution probability table with df is 1 for the X^2 value 2.668 is 0.10.
i.e CHITEST(or,er)=0.10"
Let’s see an example
Let’s see an example