The digit 5 represents 50 because it is in the tens place.
To determine the weighted moving average for period 13 using weights of 0.4 and 0.3, you calculate:
P13 = (30.7 x 0.4) + (42.0 x 0.3)
P13 = 12.28 + 12.60
P13 = 24.88.
Let RS be denoted as y.
Given that T is the midpoint of RS, this results in RT = TS = 
And W acting as the midpoint of RT, leads to
thus RW = WT = 
Given that Z is the midpoint of WS.
Meaning WZ = ZS = 
Consequently, TZ = TS - ZS = 
However, TZ is defined as x.
Thus, 
y = 8x = RS.
A) Length of RW = 
B) Length of WZ = 
C) Length of RS = y = 8x
D) Length of ZS = WZ = 3x.
An image is provided for clarification.