Home / 290.78-436.20-153.78

Finding the Fourth Proportional to 290.78, 436.20 and 153.78

Calculator

Solution

The fourth proportional to 290.78, 436.20 and 153.78 is: 230.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.78 : 436.20 = 153.78 : x
  2. Step 2: Convert to fraction form
    290.78/436.20 = 153.78/x
  3. Step 3: Cross multiply
    290.78x = 436.20 × 153.78
  4. Step 4: Simplify right side
    290.78x = 67,078.84
  5. Step 5: Solve for x
    x = 67,078.84/290.78
  6. Step 6: Final answer
    x = 230.69

Related Problems

Find fourth proportional to 145.39, 218.10 and 76.89
Half scale
Find fourth proportional to 581.56, 872.40 and 307.56
Double scale
Find fourth proportional to 291.78, 437.70 and 154.78
Similar ratio
Find fourth proportional to 436.17, 654.30 and 230.67
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.