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Finding the Fourth Proportional to 999.02, 1,378.45 and 645.05

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Solution

The fourth proportional to 999.02, 1,378.45 and 645.05 is: 890.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.02 : 1,378.45 = 645.05 : x
  2. Step 2: Convert to fraction form
    999.02/1,378.45 = 645.05/x
  3. Step 3: Cross multiply
    999.02x = 1,378.45 × 645.05
  4. Step 4: Simplify right side
    999.02x = 889,169.17
  5. Step 5: Solve for x
    x = 889,169.17/999.02
  6. Step 6: Final answer
    x = 890.04

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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.