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Finding the Fourth Proportional to 1,289.27, 1,779.66 and 765.30

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Solution

The fourth proportional to 1,289.27, 1,779.66 and 765.30 is: 1,056.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.27 : 1,779.66 = 765.30 : x
  2. Step 2: Convert to fraction form
    1,289.27/1,779.66 = 765.30/x
  3. Step 3: Cross multiply
    1,289.27x = 1,779.66 × 765.30
  4. Step 4: Simplify right side
    1,289.27x = 1,361,981.42
  5. Step 5: Solve for x
    x = 1,361,981.42/1,289.27
  6. Step 6: Final answer
    x = 1,056.39

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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.