Finding the Fourth Proportional to 420.70, 579.19 and 391.26
Calculator
Solution
The fourth proportional to 420.70, 579.19 and 391.26 is: 538.66
Step by Step Solution
- Step 1: Write the proportion equation
420.70 : 579.19 = 391.26 : x - Step 2: Convert to fraction form
420.70/579.19 = 391.26/x - Step 3: Cross multiply
420.70x = 579.19 × 391.26 - Step 4: Simplify right side
420.70x = 226,613.88 - Step 5: Solve for x
x = 226,613.88/420.70 - Step 6: Final answer
x = 538.66
Related Problems
Find fourth proportional to 210.35, 289.60 and 195.63
Half scale
Find fourth proportional to 841.40, 1,158.38 and 782.52
Double scale
Find fourth proportional to 421.70, 580.57 and 392.26
Similar ratio
Find fourth proportional to 631.05, 868.79 and 586.89
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.