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Finding the Fourth Proportional to 970.79, 1,340.24 and 640.18

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Solution

The fourth proportional to 970.79, 1,340.24 and 640.18 is: 883.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    970.79 : 1,340.24 = 640.18 : x
  2. Step 2: Convert to fraction form
    970.79/1,340.24 = 640.18/x
  3. Step 3: Cross multiply
    970.79x = 1,340.24 × 640.18
  4. Step 4: Simplify right side
    970.79x = 857,994.84
  5. Step 5: Solve for x
    x = 857,994.84/970.79
  6. Step 6: Final answer
    x = 883.81

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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.