In a test, the 10 students in group 1 get a mean score of 43%.The 15 students in group 2 get a mean score of 57%.

Hank says, " The mean score for all 25 students is 50%."
What mistake has Hank made?

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What is the correct mean score for all 25 students?

Answers

Answer 1
Answer: The mistake is that he forgot that the groups were not equal! one group was bigger than another, but he treated them as if they were equal

the real mean is calculated like this:

(43*10+15*57)/25=

(1285)/25=51.4


the real mean was 51.4




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There are 20 students in your class 3/5 of them pack a lunch which meant that will help you find the number of students in your class who pack a lunch

Answers

so 3/5 of 20 is what
'of' means multiply

3/5 of 20 means
3/5 times 20/1=(3*20)/(5*1)=60/5=12/1=12

12 pack a lunch

Explain how you can tell, without computing, whether the quotient 1/2 รท6 is greater than 1 or les than 1.

Answers

when dividing, if your first number is smaller than your second number, its going to be less than 1. 
Vice versa: if your first number is greater than your second number, its going to be greater than 1. 
Hope this helps :)
you can tell its going to be less because you are dividing a number less than 1 already

How u multiply 7/12 by 54,216

Answers

I just like to put the 54,216 over 1
(Looks like: 54,216/1)

Then just multiply across:
54,216x7/12x1

Comes out to:
379,512/12

Then do the division:
379,512/12 = 31,626

Your answer is 31,626




In a machine , a large gear completes a revolution every minute while a small gear completes a revolution every 24 seconds. If the gears are currently aligned, how much time will pass before they are aligned again?

Answers

To make the second gear be aligned with the first, it will have to rotate 5 times, a total of 120 seconds or 2 minutes will pass.

The ratio of shoes sold to sandals was 5:2.If there were 40sandals sold,how many shoes were sold?

Answers

5x-\ number\ of\ shoes\n2x-\ number\ of\ sandals\n\n40=2x\ \ \ | divide\ by\ 2\nx=20\n\n5x=5*20=100\n\nThere\ were\ 100\ shoes\ sold.

Answer:

Emily solved for a part when she should have solved for the whole. 875,000 should be the numerator of the equivalent ratio. 70 x 12,500 is 875,000. So the answer is 100 x 12,500 which is 1,250,000.

Step-by-step explanation:

Jessica is converting 60 feet per hour into yards per hour. Which conversion factor should she use?A. 1yd/3ft
B. 1h/60 min
C. 60 min/ 1h
D. 3ft/ 1yd

Answers

A. Check to make sure the conversion factor units will cancel out the original units and leave the desired units