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Finding the Fourth Proportional to 860.21, 1,290.32 and 312.18

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Solution

The fourth proportional to 860.21, 1,290.32 and 312.18 is: 468.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.21 : 1,290.32 = 312.18 : x
  2. Step 2: Convert to fraction form
    860.21/1,290.32 = 312.18/x
  3. Step 3: Cross multiply
    860.21x = 1,290.32 × 312.18
  4. Step 4: Simplify right side
    860.21x = 402,812.10
  5. Step 5: Solve for x
    x = 402,812.10/860.21
  6. Step 6: Final answer
    x = 468.27

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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.