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Finding the Fourth Proportional to 642.78, 890.70 and 603.77

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Solution

The fourth proportional to 642.78, 890.70 and 603.77 is: 836.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.78 : 890.70 = 603.77 : x
  2. Step 2: Convert to fraction form
    642.78/890.70 = 603.77/x
  3. Step 3: Cross multiply
    642.78x = 890.70 × 603.77
  4. Step 4: Simplify right side
    642.78x = 537,773.49
  5. Step 5: Solve for x
    x = 537,773.49/642.78
  6. Step 6: Final answer
    x = 836.64

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Find fourth proportional to 321.39, 445.35 and 301.88
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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.