If we collect experimental data on alcohol consumption from the same 100 individuals before and then after a course on the dangers of over drinking, we are using a * 1 point A) randomized block design. B) post-test only design. C) matched pairs design. D) randomized comparative design E) completely randomized design.

D) randomized comparative design

Step-by-step explanation:

Randomized comparative design is an experiment which uses comparison of two or more treatments, also known as an experiment designed to show differences between two samples or populations which have being exposed to two different conditions or treatments are compared to each other. In the question above data collected before was compared to data gotten after the dangers of alcohol.

is means division by fractions

step-by-step explanation:

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm