Finding the Fourth Proportional to 80.40, 120.65 and 66.99
Calculator
Solution
The fourth proportional to 80.40, 120.65 and 66.99 is: 100.52
Step by Step Solution
- Step 1: Write the proportion equation
80.40 : 120.65 = 66.99 : x - Step 2: Convert to fraction form
80.40/120.65 = 66.99/x - Step 3: Cross multiply
80.40x = 120.65 × 66.99 - Step 4: Simplify right side
80.40x = 8,082.01 - Step 5: Solve for x
x = 8,082.01/80.40 - Step 6: Final answer
x = 100.52
Related Problems
Find fourth proportional to 40.20, 60.32 and 33.50
Half scale
Find fourth proportional to 160.80, 241.29 and 133.98
Double scale
Find fourth proportional to 81.40, 122.15 and 67.99
Similar ratio
Find fourth proportional to 120.60, 180.97 and 100.49
1.5x scale
Why These Related Problems?
These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.