Home / 860-1,290-347

Finding the Fourth Proportional to 860, 1,290 and 347

Calculator

Solution

The fourth proportional to 860, 1,290 and 347 is: 520.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    860 : 1,290 = 347 : x
  2. Step 2: Convert to fraction form
    860/1,290 = 347/x
  3. Step 3: Cross multiply
    860x = 1,290 × 347
  4. Step 4: Simplify right side
    860x = 447,630
  5. Step 5: Solve for x
    x = 447,630/860
  6. Step 6: Final answer
    x = 520.50

Related Problems

Find fourth proportional to 430, 645 and 173.50
Half scale
Find fourth proportional to 1,720, 2,580 and 694
Double scale
Find fourth proportional to 861, 1,291.50 and 348
Similar ratio
Find fourth proportional to 1,290, 1,935 and 520.50
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.