Home / 714.20-1,072.40-390.20

Finding the Fourth Proportional to 714.20, 1,072.40 and 390.20

Calculator

Solution

The fourth proportional to 714.20, 1,072.40 and 390.20 is: 585.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    714.20 : 1,072.40 = 390.20 : x
  2. Step 2: Convert to fraction form
    714.20/1,072.40 = 390.20/x
  3. Step 3: Cross multiply
    714.20x = 1,072.40 × 390.20
  4. Step 4: Simplify right side
    714.20x = 418,450.48
  5. Step 5: Solve for x
    x = 418,450.48/714.20
  6. Step 6: Final answer
    x = 585.90

Related Problems

Find fourth proportional to 357.10, 536.20 and 195.10
Half scale
Find fourth proportional to 1,428.40, 2,144.80 and 780.40
Double scale
Find fourth proportional to 715.20, 1,073.90 and 391.20
Similar ratio
Find fourth proportional to 1,071.30, 1,608.60 and 585.30
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.