Home / 851.28-1,275.48-542.40

Finding the Fourth Proportional to 851.28, 1,275.48 and 542.40

Calculator

Solution

The fourth proportional to 851.28, 1,275.48 and 542.40 is: 812.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    851.28 : 1,275.48 = 542.40 : x
  2. Step 2: Convert to fraction form
    851.28/1,275.48 = 542.40/x
  3. Step 3: Cross multiply
    851.28x = 1,275.48 × 542.40
  4. Step 4: Simplify right side
    851.28x = 691,820.35
  5. Step 5: Solve for x
    x = 691,820.35/851.28
  6. Step 6: Final answer
    x = 812.68

Related Problems

Find fourth proportional to 425.64, 637.74 and 271.20
Half scale
Find fourth proportional to 1,702.56, 2,550.96 and 1,084.80
Double scale
Find fourth proportional to 852.28, 1,276.98 and 543.40
Similar ratio
Find fourth proportional to 1,276.92, 1,913.22 and 813.60
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.