Home / 230.80-345.90-139.40

Finding the Fourth Proportional to 230.80, 345.90 and 139.40

Calculator

Solution

The fourth proportional to 230.80, 345.90 and 139.40 is: 208.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    230.80 : 345.90 = 139.40 : x
  2. Step 2: Convert to fraction form
    230.80/345.90 = 139.40/x
  3. Step 3: Cross multiply
    230.80x = 345.90 × 139.40
  4. Step 4: Simplify right side
    230.80x = 48,218.46
  5. Step 5: Solve for x
    x = 48,218.46/230.80
  6. Step 6: Final answer
    x = 208.92

Related Problems

Find fourth proportional to 115.40, 172.95 and 69.70
Half scale
Find fourth proportional to 461.60, 691.80 and 278.80
Double scale
Find fourth proportional to 231.80, 347.40 and 140.40
Similar ratio
Find fourth proportional to 346.20, 518.85 and 209.10
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.