Answer:
The correct option is (A).
Step-by-step explanation:
The function representing the growth of number, in billions, of the DNA sequences in a database x years since 2010 is:

The general growth function can be represented as:

Here,
<em>y</em> = final value
<em>a</em> = initial value
<em>r</em> = growth rate
<em>t</em> = time
Com-paring the two functions we get:

This implies that the annual increase rate in number, in billions, of the DNA sequences is 32%.
Thus, the correct option is (A).
Answer:
The area is 7.5 square units
Answer: 0.4772
Step-by-step explanation:
Given : The distribution is bell shaped , then the distribution must be normal distribution.
Mean : 
Standard deviation :
The formula to calculate the z-score :-

For x = $200

For x = $280

The p-value = 

Hence, the proportion of students will spend between $200 and $280 this semester = 0.4772