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Finding the Fourth Proportional to 900.08, 1,242.40 and 638.84

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Solution

The fourth proportional to 900.08, 1,242.40 and 638.84 is: 881.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    900.08 : 1,242.40 = 638.84 : x
  2. Step 2: Convert to fraction form
    900.08/1,242.40 = 638.84/x
  3. Step 3: Cross multiply
    900.08x = 1,242.40 × 638.84
  4. Step 4: Simplify right side
    900.08x = 793,694.82
  5. Step 5: Solve for x
    x = 793,694.82/900.08
  6. Step 6: Final answer
    x = 881.80

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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.