Solution :
In a study of cereal leaf beetle in oats, researcher measured the number of beetle larvae per stem in small plot of oats after randomly applying one of two treatments : no pesticides or malathion at the rate of 0.25 lv. Per acre. Here the summary of Statistics is given by,
For Group 1 ( 1 mg ),
= 121. = 3.47 = 1.21
For Group 2 ( 2 mg ),
= 43, = 1.36 = 0.52
TO Find : 95 % confidence interval for the difference in mean.
We know that ,
( 1- ) 100% confidence interval is given by,
, )
Now ,
95 % confidence interval for difference in mean is,
( , )
= ( , )
=( , ). ......( by using z table )
= ( , )
= ( , )
= ( , 2.11+ 0.26578 )
= ( 1.8442 , 2.3757 )
i.e. 95 % confidence interval for the difference in mean number of beetle larvae per stem for the two treatments is ( 1.844 , 2.376 )
Answer : Option A is correct ( 1.844, 2.376 )
Question 2 (4 points) In a study of cereal leaf beetle damage in oats, researcher measured...