The mean weight for 5 friends is 56.6kg . if 2 more people weighting 62 and 64.5kg join them , what will be their new mean weight

58.5kg

Step-by-step explanation:

=56.6kg×5

=283kg(5 friends total weight)

=283kg+62kg+64.5kg÷7

=58.5kg

Hope this will help ya!

58.5kg

Step-by-step explanation:

To calculate mean, you add all the values, and divide the sum by the number of values. So, to find the total weight, you must multiply because multiplication is the inverse operation. 56.6 * 5= 283 kg. Two more people join, so you must add their weight to the total weight. 283 + 64.5 + 62= 409.5

Now, there are a total of 7 people (5+2=7). SO to find the mean, divide the total weight (409.5) by the total number of people (7) to find the mean.

409.5 / 7= 58.5

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places