Home / 300.80-415.55-285.41

Finding the Fourth Proportional to 300.80, 415.55 and 285.41

Calculator

Solution

The fourth proportional to 300.80, 415.55 and 285.41 is: 394.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    300.80 : 415.55 = 285.41 : x
  2. Step 2: Convert to fraction form
    300.80/415.55 = 285.41/x
  3. Step 3: Cross multiply
    300.80x = 415.55 × 285.41
  4. Step 4: Simplify right side
    300.80x = 118,603.88
  5. Step 5: Solve for x
    x = 118,603.88/300.80
  6. Step 6: Final answer
    x = 394.29

Related Problems

Find fourth proportional to 150.40, 207.78 and 142.71
Half scale
Find fourth proportional to 601.61, 831.11 and 570.83
Double scale
Find fourth proportional to 301.80, 416.93 and 286.41
Similar ratio
Find fourth proportional to 451.20, 623.33 and 428.12
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.