Ask questions and get helpful answers.

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.

  1. 👍
  2. 👎
  3. 👁
  4. ℹ️
  5. 🚩
8 answers
  1. please quickly answer i need to know this quick to explain to the class

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  2. Isn't it 70 + 80 = 150
    150 / 2 = 75 ?

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  3. Or maybe 70% (0.7) x 80% (0.8) = 0.56

    0.56 / 2 = 0.28

    So probably 28 percent?

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  4. any tutors out there know?

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  5. i mean the exact method and answer??

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  6. 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

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  7. 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!

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  8. cheers bro

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩

Answer this Question

Similar Questions

  1. earth science

    Which of these phrases describes the sun? Class G yellow star Class A white star Class M red star Class O blue star

  2. Math

    A biology class has 12 boys and 18 girls .what fraction of the class are boys? Solution. 12/30=2/5 Please tell me this correct or not.

  3. math

    In a certain class there are 12 boys and 18 girls. If the class average for an algebra exam is 90 and the boys' average score is 87, what is the girls' average score?

  4. Math

    A class is attended by 20 girls and 24 boys. Write the ratio of boys to girls in the class in lowest terms. 6:5 is this right

  5. math

    The ratio of boys to girls in a class is 7:4. If there are 9 more boys than girls how many children are in the class?

  6. maths

    In a graduating class with the same number of boys and girls, 1/8 of the girls and 5/6 of the boys are honor students. What part of the class consists of boys who are not honor students

  7. maths

    In a class there are 27 students. If there are 7 more girls than boys in the class how many students are girls?

  8. math

    there are 28 students in a class. 16 of them are boys. What is the percentage of girls in the class?

  9. math

    The ratio of boys to girls in a class room was 9:8. Half of the girls left the classroom, and then there were 15 more boys than girls. A. How many children were in the classroom in the beginning B. How many girls left the classroom?

  10. Math (Stats)

    What is the difference between class limits and class boundaries? A) Class limits are the numbers that separate classes without forming gaps between them. Class boundaries are the least and greatest numbers that can belong to the class. For integer data,

Still need help?

You can ask a new question or browse existing questions.