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Finding the Fourth Proportional to 485.40, 669.54 and 288.76

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Solution

The fourth proportional to 485.40, 669.54 and 288.76 is: 398.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.40 : 669.54 = 288.76 : x
  2. Step 2: Convert to fraction form
    485.40/669.54 = 288.76/x
  3. Step 3: Cross multiply
    485.40x = 669.54 × 288.76
  4. Step 4: Simplify right side
    485.40x = 193,336.37
  5. Step 5: Solve for x
    x = 193,336.37/485.40
  6. Step 6: Final answer
    x = 398.30

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Find fourth proportional to 242.70, 334.77 and 144.38
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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.