Joseph gives a math test to all the students in a middle school and notices that taller students have higher scores. He concludes that taller people are better at math. This conclusion is
A)
not justified, since the taller students could have cheated.
B)
justified, especially if it can be repeated on a second test.
not justified, since taller students have had more math in school
D)
justified, assuming that the test was given fairly to all students.

D) justified, assuming that the test was given fairly

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.