1 )Homer average 60 on quizzes in Math 13 and 70 the quizzes in Math 14. Yet his average of all his quizzes in Math 13 and 14 was not 65. How can that be?

2.) It is possible to have a class in which no student scores below the mean on the final exam. State precisely the conditions under which this can happen. Show that your answer is correct.
Please help me .I have no idea how to do this?

2006-11-12 00:25:49 · 4 answers · asked by magt_g 1 in Mathematics

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newton's 3rd law,,confusing,,?

when a force is exerted on an object,,there is an equal and opposite reaction,,how can anything move?as,,equal and opposite forces mean the net force is zero,,

2006-11-12 00:24:12 · 6 answers · asked by kp 2 in Physics

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Solve 2cos^2 x + cos x -1 = 0?

What I have so far is:
(2cosx -1)(cosx +1)
2cosx -1=0
2cosx=1
cosx=1/2

cosx +1=0
cosx =-1
I just don't know where to go from there...anybody?

2006-11-12 00:21:49 · 7 answers · asked by jonesin_am 1 in Mathematics

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Where can I find shortcuts for mental arithmetic on the internet?

I do quite a lot of problem-solving mathematics at home and at school, and I like to do things in my head. Where can I find such shortcuts for free on the internet?

2006-11-12 00:20:15 · 3 answers · asked by Anonymous in Mathematics

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Fireworks?

Yes, I know it was a week ago, but we went last night, and they had fireworks that went up in the sky, then down, then up again. How do they do that?

2006-11-12 00:19:35 · 3 answers · asked by emily_jane2379 5 in Chemistry

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Does carboplatin (anti-cancer drug) exhibit geometrical isomerism?

2006-11-12 00:16:00 · 1 answers · asked by Faisaltheonly1 2 in Chemistry

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Sample size?

Data sets have been obtained of advertised prices published in the current issues of local papers for 2 different towns in your area for a sample of houses for sale.

Mean prices (£'s): A=100,000 B=105,000
Variance of mean price (£ x £'s): A=12,400,000 B=12,500,000
Sample size: A=50 B=50

It is required that a 95% confidence interval has size +/-£1000 assuming the variances remain unchanged, calculate the size of samples required for such a confidence interval. (You can assume sample size of town A and B are of equal size).

Thanks for any help.

2006-11-12 00:08:40 · 1 answers · asked by joemoran7 2 in Mathematics

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How are coconut trees germinated to create the coconut fruit.?

I planted some coconut trees in the back yard a few years back and have got fruit being produced. But I don't see a lot of birds and bees flying around to help with the polination. So how does it actually take place.

2006-11-12 00:06:14 · 3 answers · asked by Anonymous in Botany

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