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Finding the Fourth Proportional to 771.19, 1,064.19 and 421.87

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Solution

The fourth proportional to 771.19, 1,064.19 and 421.87 is: 582.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.19 : 1,064.19 = 421.87 : x
  2. Step 2: Convert to fraction form
    771.19/1,064.19 = 421.87/x
  3. Step 3: Cross multiply
    771.19x = 1,064.19 × 421.87
  4. Step 4: Simplify right side
    771.19x = 448,949.84
  5. Step 5: Solve for x
    x = 448,949.84/771.19
  6. Step 6: Final answer
    x = 582.15

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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.