Rom past experience, a professor knows that the test score of a student taking her final examination is a random variable with mean 75. give an upper bound for the probability that a student’s test score will exceed 85. suppose, in addition, that the professor knows that the variance of a student’s test score is equal to 25. what can be said about the probability that a student will score between 65 and 85? how many students would have to take the examination to ensure with probability at least .9 that the class average would be within 5 of 75? do not use the central limit theorem.

it would be:

c.parallelogram.

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.