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Finding the Fourth Proportional to 890.74, 1,228.63 and 628.30

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Solution

The fourth proportional to 890.74, 1,228.63 and 628.30 is: 866.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.74 : 1,228.63 = 628.30 : x
  2. Step 2: Convert to fraction form
    890.74/1,228.63 = 628.30/x
  3. Step 3: Cross multiply
    890.74x = 1,228.63 × 628.30
  4. Step 4: Simplify right side
    890.74x = 771,948.23
  5. Step 5: Solve for x
    x = 771,948.23/890.74
  6. Step 6: Final answer
    x = 866.64

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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.