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Finding the Fourth Proportional to 840.34, 1,159.41 and 490.78

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Solution

The fourth proportional to 840.34, 1,159.41 and 490.78 is: 677.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.34 : 1,159.41 = 490.78 : x
  2. Step 2: Convert to fraction form
    840.34/1,159.41 = 490.78/x
  3. Step 3: Cross multiply
    840.34x = 1,159.41 × 490.78
  4. Step 4: Simplify right side
    840.34x = 569,015.24
  5. Step 5: Solve for x
    x = 569,015.24/840.34
  6. Step 6: Final answer
    x = 677.13

Related Problems

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Half scale
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Double scale
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Similar ratio
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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.