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Finding the Fourth Proportional to 1,312.12, 1,810.32 and 780.76

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Solution

The fourth proportional to 1,312.12, 1,810.32 and 780.76 is: 1,077.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,312.12 : 1,810.32 = 780.76 : x
  2. Step 2: Convert to fraction form
    1,312.12/1,810.32 = 780.76/x
  3. Step 3: Cross multiply
    1,312.12x = 1,810.32 × 780.76
  4. Step 4: Simplify right side
    1,312.12x = 1,413,425.44
  5. Step 5: Solve for x
    x = 1,413,425.44/1,312.12
  6. Step 6: Final answer
    x = 1,077.21

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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.