A pharmaceutical company is testing a new drug to increase
memorization ability. It takes a sample of individuals and splits
them randomly into two groups. One group is administered the drug,
and the other is given a placebo. After the drug regimen is
completed, all members of the study are given a test for
memorization ability with higher scores representing a better
ability to memorize. You are presented a 90% confidence interval
for the difference in population mean scores (with drug  without
drug) of (21.3, 10.59). What can you conclude from this
interval
1)

We do not have enough information to make a conclusion. 


2)

We are 90% confident that the difference between the two sample
means falls within the interval. 


3)

There is no significant difference between the average
memorization abilities for those on the drug compared to those not
on the drug. 


4)

We are 90% confident that the average memorization ability of
those on the drug is higher than those who are not on the
drug. 


5)

We are 90% confident that the average memorization ability of
those not on the drug is higher than those who are on the
drug. 
