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Finding the Fourth Proportional to 830.72, 1,145.12 and 620.58

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Solution

The fourth proportional to 830.72, 1,145.12 and 620.58 is: 855.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.72 : 1,145.12 = 620.58 : x
  2. Step 2: Convert to fraction form
    830.72/1,145.12 = 620.58/x
  3. Step 3: Cross multiply
    830.72x = 1,145.12 × 620.58
  4. Step 4: Simplify right side
    830.72x = 710,636.81
  5. Step 5: Solve for x
    x = 710,636.81/830.72
  6. Step 6: Final answer
    x = 855.44

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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.