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Finding the Fourth Proportional to 1,393.10, 2,089.66 and 419.20

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Solution

The fourth proportional to 1,393.10, 2,089.66 and 419.20 is: 628.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,393.10 : 2,089.66 = 419.20 : x
  2. Step 2: Convert to fraction form
    1,393.10/2,089.66 = 419.20/x
  3. Step 3: Cross multiply
    1,393.10x = 2,089.66 × 419.20
  4. Step 4: Simplify right side
    1,393.10x = 875,985.47
  5. Step 5: Solve for x
    x = 875,985.47/1,393.10
  6. Step 6: Final answer
    x = 628.80

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.