Answer:
15.1 to nearest tenth.
Step-by-step explanation:
The 7 is the lowest number so the mean would increase if taken away.
New mean = (8 + 12 + 13 + 15 + 18 + 19+21) / 7
= 106 / 7
= 15.14
Given :
Three points , P(4, 3, 4), Q(2, 1, 3), R(2, 7, 0) .
To Find :
The length of sides .
Given :
We know , length of two points P(x,y ,z) and Q(a,b,c) is given by :

Length of PQ :

Length of QR :
:
Length of RP :

Hence , this is the required solution .