Home / 401.20-553.68-285.28

Finding the Fourth Proportional to 401.20, 553.68 and 285.28

Calculator

Solution

The fourth proportional to 401.20, 553.68 and 285.28 is: 393.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    401.20 : 553.68 = 285.28 : x
  2. Step 2: Convert to fraction form
    401.20/553.68 = 285.28/x
  3. Step 3: Cross multiply
    401.20x = 553.68 × 285.28
  4. Step 4: Simplify right side
    401.20x = 157,953.83
  5. Step 5: Solve for x
    x = 157,953.83/401.20
  6. Step 6: Final answer
    x = 393.70

Related Problems

Find fourth proportional to 200.60, 276.84 and 142.64
Half scale
Find fourth proportional to 802.40, 1,107.36 and 570.56
Double scale
Find fourth proportional to 402.20, 555.06 and 286.28
Similar ratio
Find fourth proportional to 601.80, 830.52 and 427.92
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.