Answer:
The first and second choice since those symbols are the ones that apply to open circle on the number line and the 2 last ones are closed circles
Step-by-step explanation:
Given:
The function is

where, function r gives the instantaneous growth rate of a fruit fly population x days after the start of an experiment.
To find:
Number of complex and real zeros.
Time intervals for which the population increased and population deceased.
Solution:
We have,


Here, degree of function x is 3. It means, the given function has 3 zeros.
From the given graph it is clear that, the graph of function r(x) intersect x-axis at once.
So, the given function r(x) has only one real root and other two real roots are complex.
Therefore, function r has 2 complex zeros and one real zero.
Before x=6, the graph of r(x) is below the x-axis and after that the graph of r(x) is above the x-axis.
Negative values of r(x) represents the decrease in population and positive value of r(x) represents the increase in population.
Therefore, based on instantaneous growth rate, the population decreased between 0 and 6 hours and the population increased after 6 hours.
Answer:
A weak negative correlation
Step-by-step explanation:

where,



This represents a weak negative correlation
To find the contribution of each man (this is a sexist problem as women could work as well, but that’s besides the point) take 5/2 and then multiply that value by 20 and you’ll find it takes 50 hours for two men to do it.
Answer: 50 hours