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Finding the Fourth Proportional to 1,289.47, 1,780.94 and 869.10

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Solution

The fourth proportional to 1,289.47, 1,780.94 and 869.10 is: 1,200.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.47 : 1,780.94 = 869.10 : x
  2. Step 2: Convert to fraction form
    1,289.47/1,780.94 = 869.10/x
  3. Step 3: Cross multiply
    1,289.47x = 1,780.94 × 869.10
  4. Step 4: Simplify right side
    1,289.47x = 1,547,810.57
  5. Step 5: Solve for x
    x = 1,547,810.57/1,289.47
  6. Step 6: Final answer
    x = 1,200.34

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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.