Home / 1,139.35-1,570.65-981.30

Finding the Fourth Proportional to 1,139.35, 1,570.65 and 981.30

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Solution

The fourth proportional to 1,139.35, 1,570.65 and 981.30 is: 1,352.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,139.35 : 1,570.65 = 981.30 : x
  2. Step 2: Convert to fraction form
    1,139.35/1,570.65 = 981.30/x
  3. Step 3: Cross multiply
    1,139.35x = 1,570.65 × 981.30
  4. Step 4: Simplify right side
    1,139.35x = 1,541,278.85
  5. Step 5: Solve for x
    x = 1,541,278.85/1,139.35
  6. Step 6: Final answer
    x = 1,352.77

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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.