Question and Answers Forum

AllQuestion and Answers: Page 1555

Question Number 46208 Answers: 0 Comments: 1

Question Number 46194 Answers: 0 Comments: 1

Question Number 46191 Answers: 2 Comments: 0

There are three classes of form four which are 4a, 4b and 4c. in mathematics result the arithmetic mean of 4a 4b and 4c are 70, 60 and 80 and their standard deviation are 3, 3.4, and 2.5 Find the arithmetic mean and standard deviation when we combine the results of mathematics for all classes of form four. Assuming the number of students of 4a,4b and 4c are 30,45,25.

$$\mathrm{There}\:\mathrm{are}\:\mathrm{three}\:\mathrm{classes}\:\mathrm{of}\:\mathrm{form}\:\mathrm{four} \\ $$$$\mathrm{which}\:\mathrm{are}\:\mathrm{4a},\:\mathrm{4b}\:\mathrm{and}\:\mathrm{4c}. \\ $$$$\mathrm{in}\:\mathrm{mathematics}\:\mathrm{result}\:\mathrm{the}\:\mathrm{arithmetic}\:\mathrm{mean}\:\mathrm{of} \\ $$$$\mathrm{4a}\:\mathrm{4b}\:\mathrm{and}\:\mathrm{4c}\:\mathrm{are}\:\mathrm{70},\:\mathrm{60}\:\mathrm{and}\:\mathrm{80}\:\mathrm{and}\:\mathrm{their} \\ $$$$\mathrm{standard}\:\mathrm{deviation}\:\mathrm{are}\:\mathrm{3},\:\mathrm{3}.\mathrm{4},\:\mathrm{and}\:\mathrm{2}.\mathrm{5} \\ $$$$\mathrm{Find}\:\mathrm{the}\:\mathrm{arithmetic}\:\mathrm{mean}\:\mathrm{and}\:\mathrm{standard}\:\mathrm{deviation}\:\mathrm{when} \\ $$$$\mathrm{we}\:\mathrm{combine}\:\mathrm{the}\:\mathrm{results}\:\mathrm{of}\:\mathrm{mathematics}\:\mathrm{for}\: \\ $$$$\mathrm{all}\:\mathrm{classes}\:\mathrm{of}\:\mathrm{form}\:\mathrm{four}.\:\mathrm{Assuming}\:\mathrm{the} \\ $$$$\mathrm{number}\:\mathrm{of}\:\mathrm{students}\:\mathrm{of}\: \\ $$$$\mathrm{4a},\mathrm{4b}\:\mathrm{and}\:\mathrm{4c}\:\mathrm{are}\:\mathrm{30},\mathrm{45},\mathrm{25}. \\ $$$$ \\ $$

Question Number 46188 Answers: 0 Comments: 5

Using dimensional analysis , find out value of n in given expression: ∫(dx/(√(2ax−x^2 ))) = a^n sin^(−1) ((x/a) −1).

$${Using}\:{dimensional}\:{analysis}\:, \\ $$$${find}\:{out}\:{value}\:{of}\:{n}\:{in}\:{given}\:{expression}: \\ $$$$\:\:\int\frac{{dx}}{\sqrt{\mathrm{2}{ax}−{x}^{\mathrm{2}} }}\:=\:{a}^{{n}} \mathrm{sin}^{−\mathrm{1}} \left(\frac{{x}}{{a}}\:−\mathrm{1}\right). \\ $$

Question Number 46187 Answers: 0 Comments: 1

Σ_(n=1) ^∞ (1/(n×n^(1/n) ))=? please help me!!!!

$$\underset{\boldsymbol{{n}}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\mathrm{1}}{\mathrm{n}×\mathrm{n}^{\frac{\mathrm{1}}{\mathrm{n}}} }=?\:\:\:\:\:\:\:\:\mathrm{please}\:\mathrm{help}\:\mathrm{me}!!!! \\ $$$$ \\ $$

Question Number 46186 Answers: 1 Comments: 1

please help me! S=1^2 q^1 +2^2 q^2 +3^2 q^3 +...+n^2 q^n =?

$$\mathrm{please}\:\mathrm{help}\:\mathrm{me}! \\ $$$$\mathrm{S}=\mathrm{1}^{\mathrm{2}} \mathrm{q}^{\mathrm{1}} +\mathrm{2}^{\mathrm{2}} \mathrm{q}^{\mathrm{2}} +\mathrm{3}^{\mathrm{2}} \mathrm{q}^{\mathrm{3}} +...+\mathrm{n}^{\mathrm{2}} \mathrm{q}^{\mathrm{n}} =? \\ $$

Question Number 46182 Answers: 1 Comments: 4

Question Number 46180 Answers: 0 Comments: 3

Question Number 46172 Answers: 1 Comments: 0

Question Number 46171 Answers: 0 Comments: 1

find ∫ (dx/((√x)+(√(x+1)) +(√(x+2))))

$${find}\:\int\:\:\:\:\frac{{dx}}{\sqrt{{x}}+\sqrt{{x}+\mathrm{1}}\:+\sqrt{{x}+\mathrm{2}}} \\ $$

Question Number 46168 Answers: 2 Comments: 0

Question Number 46157 Answers: 1 Comments: 0

Please help. Find all the general solution of 6x + 8y + 5z = 101 . I got: x = − 48 + 45m + 4n y = 48 + 45m − 3n z = 1 − 2m Please help. Am confused.

$$\mathrm{Please}\:\mathrm{help}. \\ $$$$\:\:\:\:\:\mathrm{Find}\:\mathrm{all}\:\mathrm{the}\:\mathrm{general}\:\mathrm{solution}\:\mathrm{of}\:\:\:\:\:\:\:\mathrm{6x}\:+\:\mathrm{8y}\:+\:\mathrm{5z}\:=\:\mathrm{101}\:. \\ $$$$ \\ $$$$\mathrm{I}\:\mathrm{got}:\:\:\:\:\:\:\:\:\mathrm{x}\:=\:−\:\mathrm{48}\:+\:\mathrm{45m}\:+\:\mathrm{4n} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{y}\:=\:\:\:\:\:\mathrm{48}\:+\:\mathrm{45m}\:−\:\mathrm{3n} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{z}\:=\:\:\:\:\:\:\:\mathrm{1}\:−\:\mathrm{2m} \\ $$$$ \\ $$$$\mathrm{Please}\:\mathrm{help}.\:\:\mathrm{Am}\:\mathrm{confused}.\: \\ $$

Question Number 46156 Answers: 1 Comments: 0

Question Number 46146 Answers: 0 Comments: 3

Question Number 46144 Answers: 0 Comments: 0

Object A is in motion.A moves at a velocity of 12ms^(−2) and B is still(not moving).If A collides with B. a) Calculate the velocity at which B will move if it has mass of 70kg. and A has mass of 60kg. b) the momentum after collision. c) state the principle you applied in a) and b) above

$$\:{Object}\:{A}\:{is}\:{in}\:{motion}.{A}\:{moves}\:{at}\:{a}\:{velocity}\:{of}\: \\ $$$$\mathrm{12}{ms}^{−\mathrm{2}} \:{and}\:{B}\:{is}\:{still}\left({not}\:{moving}\right).{If}\:{A}\:{collides}\:{with}\:{B}. \\ $$$$\left.{a}\right)\:{Calculate}\:{the}\:{velocity}\:{at}\:{which}\:{B}\:{will}\:{move}\:{if}\:{it}\:{has}\:{mass} \\ $$$${of}\:\mathrm{70}{kg}.\:{and}\:{A}\:{has}\:{mass}\:{of}\:\mathrm{60}{kg}. \\ $$$$\left.{b}\right)\:{the}\:{momentum}\:{after}\:{collision}. \\ $$$$\left.{c}\left.\right)\left.\:{state}\:{the}\:{principle}\:{you}\:{applied}\:{in}\:{a}\right)\:{and}\:{b}\right)\:{above} \\ $$$$ \\ $$

Question Number 46143 Answers: 1 Comments: 0

Question Number 46139 Answers: 2 Comments: 1

A park has the shape of a regular hexagon of sides 2km each. A boy walks a distance of 5km along the sides of the park. What is the direct distance between the start point and the end point?

$$\mathrm{A}\:\mathrm{park}\:\mathrm{has}\:\mathrm{the}\:\mathrm{shape}\:\mathrm{of}\:\mathrm{a}\:\mathrm{regular}\:\mathrm{hexagon} \\ $$$$\mathrm{of}\:\mathrm{sides}\:\mathrm{2km}\:\mathrm{each}.\:\mathrm{A}\:\mathrm{boy}\:\mathrm{walks}\:\mathrm{a}\:\mathrm{distance} \\ $$$$\mathrm{of}\:\mathrm{5km}\:\mathrm{along}\:\mathrm{the}\:\mathrm{sides}\:\mathrm{of}\:\mathrm{the}\:\mathrm{park}.\: \\ $$$$\mathrm{What}\:\mathrm{is}\:\mathrm{the}\:\mathrm{direct}\:\mathrm{distance}\:\mathrm{between}\: \\ $$$$\mathrm{the}\:\mathrm{start}\:\mathrm{point}\:\mathrm{and}\:\mathrm{the}\:\mathrm{end}\:\mathrm{point}? \\ $$

Question Number 46136 Answers: 1 Comments: 0