Answer:
The second one! -5.99%
Step-by-step explanation:
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.
900 because you have to add 24 squared + 18 squared
If you were to make your own measurements, your significant digits should include all of the measurable digits (the digits that correspond to the marks on the ruler) as well as one estimated position beyond the smallest measureable digit (the 5 in 3.5 cm, and the 2 in 3.52 cm).