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Finding the Fourth Proportional to 1,287.35, 1,775.89 and 814.45

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Solution

The fourth proportional to 1,287.35, 1,775.89 and 814.45 is: 1,123.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.35 : 1,775.89 = 814.45 : x
  2. Step 2: Convert to fraction form
    1,287.35/1,775.89 = 814.45/x
  3. Step 3: Cross multiply
    1,287.35x = 1,775.89 × 814.45
  4. Step 4: Simplify right side
    1,287.35x = 1,446,360.66
  5. Step 5: Solve for x
    x = 1,446,360.66/1,287.35
  6. Step 6: Final answer
    x = 1,123.52

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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.