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Finding the Fourth Proportional to 1,642.40, 2,465.20 and 821.60

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Solution

The fourth proportional to 1,642.40, 2,465.20 and 821.60 is: 1,233.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,642.40 : 2,465.20 = 821.60 : x
  2. Step 2: Convert to fraction form
    1,642.40/2,465.20 = 821.60/x
  3. Step 3: Cross multiply
    1,642.40x = 2,465.20 × 821.60
  4. Step 4: Simplify right side
    1,642.40x = 2,025,408.32
  5. Step 5: Solve for x
    x = 2,025,408.32/1,642.40
  6. Step 6: Final answer
    x = 1,233.20

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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.