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Finding the Fourth Proportional to 780.06, 1,076.99 and 500.42

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Solution

The fourth proportional to 780.06, 1,076.99 and 500.42 is: 690.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.06 : 1,076.99 = 500.42 : x
  2. Step 2: Convert to fraction form
    780.06/1,076.99 = 500.42/x
  3. Step 3: Cross multiply
    780.06x = 1,076.99 × 500.42
  4. Step 4: Simplify right side
    780.06x = 538,939.45
  5. Step 5: Solve for x
    x = 538,939.45/780.06
  6. Step 6: Final answer
    x = 690.89

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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.