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Finding the Fourth Proportional to 520.75, 718.91 and 355.20

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Solution

The fourth proportional to 520.75, 718.91 and 355.20 is: 490.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.75 : 718.91 = 355.20 : x
  2. Step 2: Convert to fraction form
    520.75/718.91 = 355.20/x
  3. Step 3: Cross multiply
    520.75x = 718.91 × 355.20
  4. Step 4: Simplify right side
    520.75x = 255,356.83
  5. Step 5: Solve for x
    x = 255,356.83/520.75
  6. Step 6: Final answer
    x = 490.36

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Find fourth proportional to 260.38, 359.46 and 177.60
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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.