Answer:
r = 6
Step-by-step explanation:
To get the value of r we will use the pythagoras theorem a shown;
PR² = QR² + PQ²
(4+r)² = 8² + r²
Expand
16+8r+r² = 64 + r²
16 + 8r = 64
8r = 64 - 16
8r = 48
r = 48/8
r = 6
Hence the value of r is 6
The increase is an exponential increase in a multiplier

and as decimal 1.0045
Final Value = Initial Value ×

Final value =

Final value = 393 mg (to the nearest whole number)
Half life = 0.5 years
Final value =

=301 mg
I don't know what the graft is
Systematic sampling is a type of probability sampling method in which sample members from a larger population are selected according to a random starting point but with a fixed, periodic interval. This interval, called the sampling interval, is calculated by dividing the population size by the desired sample size.