Home / 991.31-1,368-571.64

Finding the Fourth Proportional to 991.31, 1,368 and 571.64

Calculator

Solution

The fourth proportional to 991.31, 1,368 and 571.64 is: 788.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.31 : 1,368 = 571.64 : x
  2. Step 2: Convert to fraction form
    991.31/1,368 = 571.64/x
  3. Step 3: Cross multiply
    991.31x = 1,368 × 571.64
  4. Step 4: Simplify right side
    991.31x = 781,996.68
  5. Step 5: Solve for x
    x = 781,996.68/991.31
  6. Step 6: Final answer
    x = 788.86

Related Problems

Find fourth proportional to 495.65, 684 and 285.82
Half scale
Find fourth proportional to 1,982.61, 2,736 and 1,143.27
Double scale
Find fourth proportional to 992.31, 1,369.38 and 572.64
Similar ratio
Find fourth proportional to 1,486.96, 2,052 and 857.45
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.