BS 2010 in General Biology with a concentration in Environmental Sciences.
I started out as a physics major (how I became acquauinted with this site), but then defected to the biology department as one fantastic professor after another cultivated my incipient interest in life science...
A weighted average (i.e. the proportion of respondents per response multiplied by the magnitude of the respone, where the "response" is size of the respondent's clan) would absolutely work, given two assumptions:
1)No two clans are the same size.
2)Answers are 100% accurate, not...
Actually, I believe the formula is STD ERROR = STD DEV / (n^0.5)
Moreover:
STD DEV = SUM OF SQUARES / ((n-1)^0.5)
I'm reluctant to use the term "degrees of freedom" because this measure doesn't come into play unless a statistical test is involved, and is not the same as the sample...
I am attempting to identify an organic "mystery compound." Having run both IR and mass spectrometry, I conjecture that the compound has a molecular mass of ~130 amu and possesses at least one -OH group. C8H18O fits this profile nicely, but no isomers of which I can conceive are commensurate...
yeah, the binomial expansion was my first thought, but because nx (40 * 0.02) is not <<1 in this case, I would have to take out the series to a large and undetermined number of terms to produce an answer that is even remotely within the ball park.
Problem:
What is the final difference in account values if $100,000 is invested in a) a project with returns of 7% / yr or b) one with returns of 5% / yr. Let the period of investment be 40 years.
This problem is quite simple in theory, and I know the answer should be 100,000(1.07^40 -...
Two bodies in space always exert a gravitational force on each other, F = (G*m1*m2)/r^2 which pulls each body towards the other... this is Newton's third law, the postulate of equal/opposite forces... if the Earth exerts on a gravitational force on a falling object, that same object must...
i'm currently unable to view the images you attached... what were x,y, and z again?
EDIT: i recall r and s being 1 and -1, right? if that's the case (1 - sin(r+s) + cos(r+s) should be equal to (1 - sin0 + cos0) = (1 - 0 +1) = 2, not zero..
images loaded fine for me...
anyhow, you have done everything correctly thus far. just plug the given values for s and r into the final expression 2(x+y+z)(1 - sin(r+s) + cos(r+s))
you will never go awry if you always plug in given values last
First calculate force of static friction (force required to make the block move):
F_{f} = \mu_{s} m g = 0.4(25.5)(9.8) = 99.96 N
Now use this to find the mass of sand:
F_{f} = F_{w} = m g ==> m = F_{f}/g = 99.96/9.8 = 10.2 kg
but of course we must subtract the mass of the bucket, so the mass...