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Finding the Fourth Proportional to 1,319.81, 1,979.81 and 345.89

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Solution

The fourth proportional to 1,319.81, 1,979.81 and 345.89 is: 518.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,319.81 : 1,979.81 = 345.89 : x
  2. Step 2: Convert to fraction form
    1,319.81/1,979.81 = 345.89/x
  3. Step 3: Cross multiply
    1,319.81x = 1,979.81 × 345.89
  4. Step 4: Simplify right side
    1,319.81x = 684,784.85
  5. Step 5: Solve for x
    x = 684,784.85/1,319.81
  6. Step 6: Final answer
    x = 518.85

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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.