Home / 1,420-2,130-394

Finding the Fourth Proportional to 1,420, 2,130 and 394

Calculator

Solution

The fourth proportional to 1,420, 2,130 and 394 is: 591

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420 : 2,130 = 394 : x
  2. Step 2: Convert to fraction form
    1,420/2,130 = 394/x
  3. Step 3: Cross multiply
    1,420x = 2,130 × 394
  4. Step 4: Simplify right side
    1,420x = 839,220
  5. Step 5: Solve for x
    x = 839,220/1,420
  6. Step 6: Final answer
    x = 591

Related Problems

Find fourth proportional to 710, 1,065 and 197
Half scale
Find fourth proportional to 2,840, 4,260 and 788
Double scale
Find fourth proportional to 1,421, 2,131.50 and 395
Similar ratio
Find fourth proportional to 2,130, 3,195 and 591
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.