Determine whether the study depicts an observational study or an experiment. Eighth dash grade students are randomly divided into two groups. a. One group is taught English using traditional techniques. b. The other is taught English using a reform method. After 1 year comma each group is given an achievement test to compare its proficiency with that of the other group. Choose the correct description of the study.

The study is an experiment.

Step-by-step explanation:

From the information provided, Eighth-grade students are randomly divided into two groups.

==> The first group is taught English using traditional techniques.

==> The second group is taught English using a reform method.

The main goal is to compare the proficiency in English of the two groups. This is purely an experimental study. In this case, human experiment.

The experimental tools is the English techniques being served or taught and the experimental units are the Eighth-grade students which were grouped into 2 groups and served different techniques.

At the end of the study, the researchers wish to know the most effective or efficient method of teaching English to gain excellent proficiency of the language. They should be able to know whether Traditional techniques is better than the Reform method or vice versa.

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.

so, converting firstly the mixed fractions to improper fractions and then "adding".