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Finding the Fourth Proportional to 898.36, 1,240.86 and 815.20

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Solution

The fourth proportional to 898.36, 1,240.86 and 815.20 is: 1,126.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    898.36 : 1,240.86 = 815.20 : x
  2. Step 2: Convert to fraction form
    898.36/1,240.86 = 815.20/x
  3. Step 3: Cross multiply
    898.36x = 1,240.86 × 815.20
  4. Step 4: Simplify right side
    898.36x = 1,011,549.07
  5. Step 5: Solve for x
    x = 1,011,549.07/898.36
  6. Step 6: Final answer
    x = 1,126.00

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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.