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Finding the Fourth Proportional to 1,289.94, 1,779.47 and 817.05

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Solution

The fourth proportional to 1,289.94, 1,779.47 and 817.05 is: 1,127.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.94 : 1,779.47 = 817.05 : x
  2. Step 2: Convert to fraction form
    1,289.94/1,779.47 = 817.05/x
  3. Step 3: Cross multiply
    1,289.94x = 1,779.47 × 817.05
  4. Step 4: Simplify right side
    1,289.94x = 1,453,911.88
  5. Step 5: Solve for x
    x = 1,453,911.88/1,289.94
  6. Step 6: Final answer
    x = 1,127.12

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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.