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Finding the Fourth Proportional to 624.75, 861.77 and 491.78

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Solution

The fourth proportional to 624.75, 861.77 and 491.78 is: 678.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    624.75 : 861.77 = 491.78 : x
  2. Step 2: Convert to fraction form
    624.75/861.77 = 491.78/x
  3. Step 3: Cross multiply
    624.75x = 861.77 × 491.78
  4. Step 4: Simplify right side
    624.75x = 423,798.17
  5. Step 5: Solve for x
    x = 423,798.17/624.75
  6. Step 6: Final answer
    x = 678.35

Related Problems

Find fourth proportional to 312.38, 430.89 and 245.89
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.