Answer:
The region between one standard deviation from the mean is (400,600) which should be 68.27% of the data.
Step-by-step explanation:
The mean of this data set is 500 and the standard deviation is 100. The data that are within one standard deviation of the mean, must be in the range between 400 and 600, which according to the normal curve should be about 68.27% of the samples. The shaded region is shown in red on the attached figure.
Answer:
Step-by-step explanation:
Given that Prof Liu gave the same quiz to the students in her morning class and in her afternoon class. the average score for the two classes combined was 84.
(1) The average score for the students in the morning class was 80
(2) the average score for the students in the afternoon class was 86
Let m be the no of students in I class and n in II class
Total of I class = 80m and
Total of II class = 86n
Total of both classes = 80m +86n
Average =
m cannot be equal to n because in that case average would have been 83
If m >n, then say n =m+a
then average =
Because 86 is more times added, average score would decrease hence we would not get 84.
So I class is getting less score of 80 to get a score average of more than 83 (the average) the class II should have more students.