Home / 608.40-839.43-387.57

Finding the Fourth Proportional to 608.40, 839.43 and 387.57

Calculator

Solution

The fourth proportional to 608.40, 839.43 and 387.57 is: 534.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    608.40 : 839.43 = 387.57 : x
  2. Step 2: Convert to fraction form
    608.40/839.43 = 387.57/x
  3. Step 3: Cross multiply
    608.40x = 839.43 × 387.57
  4. Step 4: Simplify right side
    608.40x = 325,337.89
  5. Step 5: Solve for x
    x = 325,337.89/608.40
  6. Step 6: Final answer
    x = 534.74

Related Problems

Find fourth proportional to 304.20, 419.72 and 193.79
Half scale
Find fourth proportional to 1,216.80, 1,678.86 and 775.14
Double scale
Find fourth proportional to 609.40, 840.81 and 388.57
Similar ratio
Find fourth proportional to 912.60, 1,259.15 and 581.36
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.