The Answer Is 42.............................................
25x² + 1 = 5
25x² + 1 - 5 = 0
25x² - 4 = 0 By difference of two squares
(5x)² - (2)² = 0
(5x - 2)(5x + 2) = 0
5x - 2 = 0 or 5x + 2 = 0
5x = 0 + 2 5x = 0 - 2
5x = 2 5x = -2
x = 2/5 x = -2/5
x = 0.4 x = -0.4
x = + 0.4 or -0.4
The expected value of the inseam length of the jeans is found as
30% of 30+ 25% of 32+ 10% of 34+ 10% of 36 + 10% of 38 + 15% of 40
= 
= 
Hence, the third option 33.8 is the correct expected value.
Given: The information provided in the table shown
To Determine: From the options provided, the correct option that best describe the information given in the table
Solution
Given that 28% of the children used toothpaste. From the table

Let us calculate the percentage of adult that used toothpaste

Hence, a smaller percentage of adults (about 11%) use the toothpaste.
The correct option is OPTION C