The weighted mean if the quizzes each count for 20% and the final exam counts for 40% of the final grade rounded to one decimal place is 18.8
Mean is the average set of numbers.
Given the Elaine quiz grades to be 90, 83 and 64
40% of the final grade will be expressed as:
20% of 90 = 18
20% of 83 = 16.6
20% of 64 = 12.8
If the quiz count for 40% of the final grade, then her final grade will be:
40% of 69 = 27.6
Take the weighted mean
Mean = Sum of scores/Sample size
Mean = (18+16.6+12.8+27.6)/4
Mean = 75/5
Mean = 18.75
Hence the weighted mean if the quizzes each count for 20% and the final exam counts for 40% of the final grade rounded to one decimal place is 18.8
Learn more here: https://brainly.com/question/23035749