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Finding the Fourth Proportional to 643.80, 888.30 and 410.76

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Solution

The fourth proportional to 643.80, 888.30 and 410.76 is: 566.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.80 : 888.30 = 410.76 : x
  2. Step 2: Convert to fraction form
    643.80/888.30 = 410.76/x
  3. Step 3: Cross multiply
    643.80x = 888.30 × 410.76
  4. Step 4: Simplify right side
    643.80x = 364,878.11
  5. Step 5: Solve for x
    x = 364,878.11/643.80
  6. Step 6: Final answer
    x = 566.76

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Half scale
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Double scale
Find fourth proportional to 644.80, 889.68 and 411.76
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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.