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Finding the Fourth Proportional to 839.78, 1,258.56 and 619.38

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Solution

The fourth proportional to 839.78, 1,258.56 and 619.38 is: 928.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.78 : 1,258.56 = 619.38 : x
  2. Step 2: Convert to fraction form
    839.78/1,258.56 = 619.38/x
  3. Step 3: Cross multiply
    839.78x = 1,258.56 × 619.38
  4. Step 4: Simplify right side
    839.78x = 779,526.89
  5. Step 5: Solve for x
    x = 779,526.89/839.78
  6. Step 6: Final answer
    x = 928.25

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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.