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Finding the Fourth Proportional to 780.43, 1,165.01 and 669.55

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Solution

The fourth proportional to 780.43, 1,165.01 and 669.55 is: 999.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.43 : 1,165.01 = 669.55 : x
  2. Step 2: Convert to fraction form
    780.43/1,165.01 = 669.55/x
  3. Step 3: Cross multiply
    780.43x = 1,165.01 × 669.55
  4. Step 4: Simplify right side
    780.43x = 780,032.45
  5. Step 5: Solve for x
    x = 780,032.45/780.43
  6. Step 6: Final answer
    x = 999.49

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.