Home / 306.11-421.57-278.77

Finding the Fourth Proportional to 306.11, 421.57 and 278.77

Calculator

Solution

The fourth proportional to 306.11, 421.57 and 278.77 is: 383.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.11 : 421.57 = 278.77 : x
  2. Step 2: Convert to fraction form
    306.11/421.57 = 278.77/x
  3. Step 3: Cross multiply
    306.11x = 421.57 × 278.77
  4. Step 4: Simplify right side
    306.11x = 117,521.07
  5. Step 5: Solve for x
    x = 117,521.07/306.11
  6. Step 6: Final answer
    x = 383.92

Related Problems

Find fourth proportional to 153.06, 210.79 and 139.39
Half scale
Find fourth proportional to 612.22, 843.14 and 557.54
Double scale
Find fourth proportional to 307.11, 422.95 and 279.77
Similar ratio
Find fourth proportional to 459.17, 632.36 and 418.16
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.