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Finding the Fourth Proportional to 556.20, 766.73 and 390.76

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Solution

The fourth proportional to 556.20, 766.73 and 390.76 is: 538.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    556.20 : 766.73 = 390.76 : x
  2. Step 2: Convert to fraction form
    556.20/766.73 = 390.76/x
  3. Step 3: Cross multiply
    556.20x = 766.73 × 390.76
  4. Step 4: Simplify right side
    556.20x = 299,606.47
  5. Step 5: Solve for x
    x = 299,606.47/556.20
  6. Step 6: Final answer
    x = 538.67

Related Problems

Find fourth proportional to 278.10, 383.37 and 195.38
Half scale
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Double scale
Find fourth proportional to 557.20, 768.11 and 391.76
Similar ratio
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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.