<span>By allowing the ground to grow fallow, it absorbs, through rain and natural means the nitrogen and phosphorus necessary in order to fertilize plants. Then once the field is plowed, the elements mix together to form the foundation by which the seeds can be nurtured and grow more effectively.</span>
D. Chloroplast is only found in plant cells not in animal cells
<span>The answer is Due to heating of the air by the engine exhaust. Contrails are formed when the hot exhaust of the plane engines is rapidly cooled by the cold air in the upper atmosphere. The water vapor in the engine exhaust, formed in the combustion of fuel, freezes immediately to ice crystals due to the low pressure and -36oC temperatures in the 8000 m altitude in which the planes cruise. </span>
Given: The systolic arterial blood pressure observed for 20 dogs is normally distributed with a mean of 152 mm of mercury (Hg) and a standard deviation of 18 mm of Hg.
To find: P(100 < 152)
Method: Calculation of Z-Score followed by the probability or area of the bell curve at X = 100.
Solution:
Mean u = 152, std s = 18
Z score = 
The value of P(100<152) is calculated by looking at the value of Z in the Z score for the standard normal distribution given in the image.
P(Z=-2.89) = 0.0019
The P(Z = -2.89) corresponds to the area in the left tail of the bell curve.
Thus the probability of 100 mm Hg blood pressure is 0.0019.