It takes 9 hrs 19.8 minutes for the student teacher to grade the exams if they worked alone
<u>Solution:</u>
Let the efficiency of the school teacher be “x” and the efficiency of the student teacher be “y”
Here the word efficiency means the rate of doing work
Let the total work to be completed be W
According to the question,
The time taken by the school teacher to complete the work is 7 hrs.
So we can write it in equation form
---- eqn 1
where W is the total work and x is the efficiency
Similarly for student teacher and school teacher doing the work simultaneously, we can write the equation as
Equating eqn 1 and 2
7x = 4x + 4y
3x = 4y
So in ratio x : y = 4 : 3
Now putting value of x = 4 in equation (1) we get total work to be 28
Now, <em>total time taken by the student teacher = total work ÷ efficiency of student teacher</em>
Hence, total time taken by the student teacher = 28 ÷ 3 = 9.33 hrs
= 9 hrs 19.8 minutes
Hence it takes 9 hrs 19.8 minutes for the student teacher to grade the exams if they worked alone
Answer:
The cumulative frequency plot is also attached below.
Step-by-step explanation:
The data provided is as follows:
Age Group Frequency
0 - 9 34.9
10 - 19 35.7
20 - 29 36.8
30 - 39 38.1
40 - 49 37.8
50 - 59 37.8
60 - 69 34.5
70 - 79 27.2
80 - 89 18.8
90 - 99 7.7
100 - 109 1.7
Consider the Excel output attached.
The cumulative frequency are computed in the Excel sheet.
The cumulative frequency plot is also attached below.
From the cumulative frequency plot it can be seen that in the future most people will belong to a higher age group rather then the lower ones.
