The domain would be (negaive infinity, positive infinity)
Assume that the bank balance started at zero. Enter the income and outgo in chronological order: $300 - $50 - $75 + $225
Find the sum. This sum will represent the amount left in the account after the $225 deposit:
$250 - $75 + $225, or
$175 + $225 = $400 The final balance will be $400.
Correct Answer:Option A. 0.01
Solution:This is a problem of statistics and uses the concept of normal distributions. We need to convert the score of 90 into z-score and then find the desired probability from standard normal distribution table.
Converting 90 to z-score:

Now we are to find the probability of z score being more than 2.33. From the z-table the probability comes out to be 0.01.
Therefore, we can conclude that the probability of class average is greater than 90 is 0.01.
Make a ratio, then cross multiply.
4/30=x/48
30x=4x48
30x=192
x=6.4