Question

the mean height of 20 boys and 14 girls is 161cm.if the mean height of the 14 girls is 151cm,calculate the mean height of the 20 boys.

Answer 1

Is this geometry @rids?

Answer 2

no it is statistics

Answer 3

Oh im sorry...I am in geometry..I dont know this....

Answer 4

do you know any one who does?

Answer 5

\[the mean height of 20 boys and 14 girls is 161cm.if the mean height of the 14 girls is 151cm,calculate the mean height of the 20 boys.\]

Answer 6

let me check

Answer 7

use what you know, how do you determine a mean?

Answer 8

Well the simple way to do it,\[151+?\div2=161\]

Answer 9

formula of mean=mean=sum of fx / f

Answer 10

\[the mean height of 20 boys and 14 girls is 161cm.if the mean height of the 14 girls is 151cm,calculate the mean height of the 20 boys.\]

Answer 11

The mean Heights of the Males would be 171 cm

Answer 12

\[\large \frac{(b_1+b_2+...+b_{20})+(g_1+g_2+...+g_{14)}}{20+14}=N\]
\[(b_1+b_2+...+b_{20})+(g_1+g_2+...+g_{14)}=34~N\]
\[(b_1+b_2+...+b_{20})=34~N-(g_1+g_2+...+g_{14})\]
\[\frac{(b_1+b_2+...+b_{20})}{20}=\frac{34}{20}~N-\frac{1}{20}(g_1+g_2+...+g_{14})\]
\[\frac{(b_1+b_2+...+b_{20})}{20}=\frac{34}{20}~N-\frac{1}{20}~\frac{14}{14}(g_1+g_2+...+g_{14})\]

Answer 13

\[boy_{\mu}=\frac{34(161)}{20}-\frac{14(151)}{20}\]
looks about right to me

Answer 14

I am in the eighth grade . do you have a simpler solution?

Answer 15

math IS the simplest solution. and no, i cant think of a different way to approach that.

Answer 16

thank u so much for all your help, I have another question.The heights of three plants A,B and C in a garden are in a ratio 2:3:5.their mean heights is 30cm.(a)find the height of plant B (b) if another plant D is added to the garden and the mean height of the four plants is now 33cm,find the height of plant d.

Answer 17

let the heights be 2k, 3k, and 5k, and work the mean\[\frac{2k+3k+5k}{3}=30\]
solve for k to know what 3k is equal to

Answer 18

once you know k, we know the values for A,B C

\[\frac{(A+B+C)+D}{4}=33\]solve for D since its the only unknown

Answer 19

D = 33(4) - 10k, looks about right

Answer 20

we are getting two variables D and K

Answer 21

you there?

Answer 22

k is from the setup in part a, once we know k we know the heights of A,B,C

the setup in part b, uses the knowledge gained from part a, and all we have to solve for is D since k is known by then

Answer 23

the mean of three numbers x,y and z is 6 and the mean of five numbers x,y,z,a,and b is 8. Find the mean of a and b.