3. The expected value of x is （ ）
A: 2.0
B: 2.1
C: 2.6
D: indeterminate
A: 2.0
B: 2.1
C: 2.6
D: indeterminate
举一反三
- 3. The variance of y is ( ) A: 0.44 B: 0.66 C: 4.6 D: indeterminate
- The value of expression ~(5|3) is not equal to the value of expression ~5|3.
- 我国水资源总量约为()万亿m^3/年， A: 2.0 B: 2.5 C: 2.6 D: 2.8
- 2020年，我国经济增长速度为（ ）。 A: 2.1% B: 2.3% C: 2.6% D: 3.2%
- 4. If all the x values were increased by 5 in this table, then the answer to question 3 would be （ ） A: Unchanged B: increased by 5 C: multiplied by 5 D: indeterminate