Answer:
The answer to your question is Molarity = 0.41
Step-by-step explanation:
Data
mass of KNO₃ = 76.6 g
volume = 1.84 l
density = 1.05 g/ml
Process
1.- Calculate the molecular mass of KNO₃
molecular mass = 39 + 14 + (16 x 3) = 101 g
2.- Calculate the number of moles
 101 g of KNO₃ --------------- 1 mol
 76.6 g of KNO₃ ------------ x
 x = (76.6 x 1) / 101
 x = 0.76 moles
3.- Calculate molarity
Molarity = 

Substitution
Molarity = 

Result 
Molarity = 0.41