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Finding the Fourth Proportional to 1,312.29, 1,810.91 and 781.23

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Solution

The fourth proportional to 1,312.29, 1,810.91 and 781.23 is: 1,078.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,312.29 : 1,810.91 = 781.23 : x
  2. Step 2: Convert to fraction form
    1,312.29/1,810.91 = 781.23/x
  3. Step 3: Cross multiply
    1,312.29x = 1,810.91 × 781.23
  4. Step 4: Simplify right side
    1,312.29x = 1,414,737.22
  5. Step 5: Solve for x
    x = 1,414,737.22/1,312.29
  6. Step 6: Final answer
    x = 1,078.07

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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.