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Finding the Fourth Proportional to 638.75, 881.45 and 355.16

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Solution

The fourth proportional to 638.75, 881.45 and 355.16 is: 490.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.75 : 881.45 = 355.16 : x
  2. Step 2: Convert to fraction form
    638.75/881.45 = 355.16/x
  3. Step 3: Cross multiply
    638.75x = 881.45 × 355.16
  4. Step 4: Simplify right side
    638.75x = 313,052.58
  5. Step 5: Solve for x
    x = 313,052.58/638.75
  6. Step 6: Final answer
    x = 490.10

Related Problems

Find fourth proportional to 319.38, 440.72 and 177.58
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Double scale
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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.