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Finding the Fourth Proportional to 1,289.86, 1,779.90 and 730.30

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Solution

The fourth proportional to 1,289.86, 1,779.90 and 730.30 is: 1,007.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.86 : 1,779.90 = 730.30 : x
  2. Step 2: Convert to fraction form
    1,289.86/1,779.90 = 730.30/x
  3. Step 3: Cross multiply
    1,289.86x = 1,779.90 × 730.30
  4. Step 4: Simplify right side
    1,289.86x = 1,299,860.97
  5. Step 5: Solve for x
    x = 1,299,860.97/1,289.86
  6. Step 6: Final answer
    x = 1,007.75

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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.