Question

please solve this question... and explain all steps..​

Answer 1

Steps for first question

1. Total number is 100, find relation of $f_1$ and $f_2$.
2. Mean of the data is 53, make an expression.
3. Find $f_1$ and $f_2$.

Step 1

$f_1+f_2+15+17+21=100$

$f_2=100-53-f_1$

∴ $f_2=47-f_1$

Step 2

$\frac{10*15+30*f_1+50*21+70*(47-f_1)+90*17}{100} =53$

...

∴ $f_1=18$

Step 3

∴ $f_1=18$, $f_2=29$

Steps for second question

(This may be wrong if data can be non-natural number.)

(This may be wrong if there can be at least two same data.)

1. Two data in the middle are 28 and 29.
2. Data 28 and 29 divides the data in half.
3. (Number of data in the left) = (Number of data in the right) = 30
4. Find x and y.

Step 1

Pass

Step 2

Because data 28 and 29 are in 20-30, left gets -1 and right gets +1.

(Number of data in the left) = $5+8+x-1$ = $x+12$

(Number of data in the right) = $15+y+5+1$ = $y+21$

Step 3

$x+12=30$

$y+21=30$

Step 4

∴ $x=18$, $y=9$

Thank You