Finding the Fourth Proportional to 129.21, 178.22 and 87.75
Calculator
Solution
The fourth proportional to 129.21, 178.22 and 87.75 is: 121.03
Step by Step Solution
- Step 1: Write the proportion equation
129.21 : 178.22 = 87.75 : x - Step 2: Convert to fraction form
129.21/178.22 = 87.75/x - Step 3: Cross multiply
129.21x = 178.22 × 87.75 - Step 4: Simplify right side
129.21x = 15,638.81 - Step 5: Solve for x
x = 15,638.81/129.21 - Step 6: Final answer
x = 121.03
Related Problems
Find fourth proportional to 64.61, 89.11 and 43.88
Half scale
Find fourth proportional to 258.42, 356.44 and 175.50
Double scale
Find fourth proportional to 130.21, 179.60 and 88.75
Similar ratio
Find fourth proportional to 193.82, 267.33 and 131.63
1.5x scale
Why These Related Problems?
These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.