Answer:
Marilee wants to earn an "A" in a class and needs an overall average of at least Her test grades are 88 , 92,100 , and 80 . The average of her quizzes is 90 and counts as one test grade. The final exam counts as 2.5 test grades. What scores on the final exam would result in Marilee's overall average of 92 or greater? (See Example 9
The answer to number 11 is 136.5
244 - 165 = 79 . . . . one standard deviation
323 - 244 = 79 . . . . one standard deviation
The range of scores is ±1 standard deviation from the mean. The empirical rule says
68% of scores lie in that range.
2/3 and 12/18 are equivalent fractions, and 12+18 = 30 so the answer is 12:18