Mr brown gives his class a test.
The 10 girls in the class get a mean mark of 70 percent.
The 15 boys in the class get a mean mark of 80 percent.
Nick says that because the mean of 70 and 80 is 75 then the mean mark for the whole class in the test is 75 percent.
Nick is not correct.
Is the correct mean mark less than or greater than 75 percent.
You must justify your answer!
Please answer question above i have no clue but as i have to show my work, here it is:
There are more girls than boys not an equal amount of girls and boys so the mean cannot be the middle number of 70 and 80.
Please answer and quickly with step by step clear help.
girls- 10 x 70 = 700
boys- 15 x 80 = 1200
700+1200 = 1900
1900/25 = 76%
76% is more than 75%
so the answer is more than
girls- 10 x 70 = 700
boys- 15 x 80 = 1200
700+1200 = 1900
1900/25 = 76%
76% is more than 75%
so the answer is more than
im not a teacher but i think this is the answer
im in year 9 by the way!
please quickly answer i need to know this quick to explain to the class
any tutors out there know?
i mean the exact method and answer??
cheers bro
To find the correct mean mark for the whole class, we need to take into account the number of students in each group and the mean mark of each group. Here's how you can calculate it step by step:
1. Calculate the sum of all the girls' marks:
- Number of girls: 10
- Mean mark of girls: 70%
- Total sum of girls' marks = Number of girls * Mean mark of girls = 10 * 70% = 700%
2. Calculate the sum of all the boys' marks:
- Number of boys: 15
- Mean mark of boys: 80%
- Total sum of boys' marks = Number of boys * Mean mark of boys = 15 * 80% = 1200%
3. Calculate the total number of students in the class:
- Total number of students = Number of girls + Number of boys = 10 + 15 = 25
4. Calculate the overall mean mark for the entire class:
- Total mean mark = (Total sum of girls' marks + Total sum of boys' marks) / Total number of students
- Total mean mark = (700% + 1200%) / 25 = 1900% / 25 = 76%
Therefore, the correct mean mark for the whole class is 76%, which is greater than 75%.
Or maybe 70% (0.7) x 80% (0.8) = 0.56
0.56 / 2 = 0.28
So probably 28 percent?
Isn't it 70 + 80 = 150
150 / 2 = 75 ?