Divide the set of data into four quartiles. 4, 5, 7, 11, 12, 15, 16, 18

First group =  

✔ 4 and 5

Second group =  

✔ 7 and 11

Third group =  

✔ 12 and 15

Fourth group =  

✔ 16 and 18

correct on edge 2021

Step-by-step explanation:

other answer is correct. i had used the radius of the radius somehow. a website:

< xcy ≅ < xby

step-by-step explanation:

in δcax and δbax,

so, δcax ≅ δbax (side-angle-side or sas)

since δcax ≅ δbax, we can conclude < acx ≅ < abx

in δacy and δaby,

so, δacy ≅ δaby (side-angle-side or sas)

since δacy ≅ δaby, we can conclude < acy ≅ < aby

now,

< acy ≅ < aby

=> < acx + < xcy ≅ < abx + < xby

=> < acx + < xcy ≅ < acx + < xby   (since < acx ≅ < abx already proved above)

subtracting < acx from both sides, we get

< acx + < xcy -< acx ≅ < acx + < xby -< acx

cancelling out < acx and -< acx from both sides, we get

< xcy ≅ < xby (proved)