Home / 311.68-430.20-213.40

Finding the Fourth Proportional to 311.68, 430.20 and 213.40

Calculator

Solution

The fourth proportional to 311.68, 430.20 and 213.40 is: 294.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.68 : 430.20 = 213.40 : x
  2. Step 2: Convert to fraction form
    311.68/430.20 = 213.40/x
  3. Step 3: Cross multiply
    311.68x = 430.20 × 213.40
  4. Step 4: Simplify right side
    311.68x = 91,804.68
  5. Step 5: Solve for x
    x = 91,804.68/311.68
  6. Step 6: Final answer
    x = 294.55

Related Problems

Find fourth proportional to 155.84, 215.10 and 106.70
Half scale
Find fourth proportional to 623.36, 860.40 and 426.80
Double scale
Find fourth proportional to 312.68, 431.58 and 214.40
Similar ratio
Find fourth proportional to 467.52, 645.30 and 320.10
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.