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Finding the Fourth Proportional to 920.21, 1,378.15 and 480.42

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Solution

The fourth proportional to 920.21, 1,378.15 and 480.42 is: 719.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.21 : 1,378.15 = 480.42 : x
  2. Step 2: Convert to fraction form
    920.21/1,378.15 = 480.42/x
  3. Step 3: Cross multiply
    920.21x = 1,378.15 × 480.42
  4. Step 4: Simplify right side
    920.21x = 662,089.71
  5. Step 5: Solve for x
    x = 662,089.71/920.21
  6. Step 6: Final answer
    x = 719.50

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Half scale
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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.