Home / 440.80-660.38-257.66

Finding the Fourth Proportional to 440.80, 660.38 and 257.66

Calculator

Solution

The fourth proportional to 440.80, 660.38 and 257.66 is: 386.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    440.80 : 660.38 = 257.66 : x
  2. Step 2: Convert to fraction form
    440.80/660.38 = 257.66/x
  3. Step 3: Cross multiply
    440.80x = 660.38 × 257.66
  4. Step 4: Simplify right side
    440.80x = 170,153.51
  5. Step 5: Solve for x
    x = 170,153.51/440.80
  6. Step 6: Final answer
    x = 386.01

Related Problems

Find fourth proportional to 220.40, 330.19 and 128.83
Half scale
Find fourth proportional to 881.60, 1,320.76 and 515.32
Double scale
Find fourth proportional to 441.80, 661.88 and 258.66
Similar ratio
Find fourth proportional to 661.20, 990.57 and 386.49
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.