Home / 1,215.40-1,677.60-718.12

Finding the Fourth Proportional to 1,215.40, 1,677.60 and 718.12

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Solution

The fourth proportional to 1,215.40, 1,677.60 and 718.12 is: 991.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,215.40 : 1,677.60 = 718.12 : x
  2. Step 2: Convert to fraction form
    1,215.40/1,677.60 = 718.12/x
  3. Step 3: Cross multiply
    1,215.40x = 1,677.60 × 718.12
  4. Step 4: Simplify right side
    1,215.40x = 1,204,718.11
  5. Step 5: Solve for x
    x = 1,204,718.11/1,215.40
  6. Step 6: Final answer
    x = 991.21

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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.