Answer:

Explanation:
The computation of the probability of the selected person is undergraduate or a female is shown below:
Total person in psychology lab
= Male doctoral students + female doctoral students + male undergraduates + female undergraduates
= 8 + 6 + 16 + 9
= 39
Now the probability would be
= (Female doctoral students + male undergraduates + female undergraduates) ÷ (Total persons)

= 
Answer:
Traditional plowing and tilling is the standard method used by farmers to control weeds. If they use the no-till (conservation-tillage) approach, they must use additional herbicides to control weeds before they plant.
Explanation:
Studies attempting to relate personality traits to a potential for developing substance abuse show that no single trait or combination of traits predicts substance abuse.
The factors that can affect the development and acceleration of abuse, are the relationship between the family, and overall happiness.
Answer: Brakes
It is considered in the states that trailers having a GVWR of 1,500 pounds or more are required to have brakes on all wheels. For automobile manufacturers, they suggest trailer brakes shall be used with even lighter weights.
Two types of brakes:
The surge breaks and the electrically-activated breaks