Consider the following hypothetical population and compute the statistical measures below: #births = 50,000; #deaths = 10,000; #immigrants = 5,000; #emigrants = 20,000; mid-year population = 1,000,000. show formulas and all relevant work.
br =
dr =
apgr =
dt =
adjusted (true) growth rate =
adjusted (true) doubling time =

The birth rate refers to an average number of births in one year per thousand individuals in the population at mid-year.  

BR = (total birth in an annum / total population in mid year) * 1000

BR = (50000 / 1000000) * 1000 = 50

Death rate refers to an average number of death in an annum per thousand individuals in a population at mid year. Thus,  

DR = (total death / total population in mid year) * 1000

DR = (10000 / 1000000) * 1000 = 10

Annual population growth rate or APGR is calculated as:  

APGR = (Birth rate - Death rate) / Death rate

APGR = (50 - 10) / 10 = 4.0 %

Doubling time is the whole sum time needed for a population to get double in size. It is calculated as DT = ln (2) / growth rate

70 / 4.0 = 17.5 years

Thus, population will get double in 17.5 years.  

Adjusted (true) growth rate is equal to APGR + (NMR / Death rate)

And NMR = [(immigrants -emigrants) / total population] * 1000

NMR = [(5000 - 20000) / 1000000] * 1000 = -15

Thus, Adjusted (True) growth rate = 4.0 + (-15 /10) = -6%

The adjusted (true) doubling time = ln (2) / Adjusted growth rate  

= 70 / -6 = -11.66

This negative sign shows that it will never get double in such situation.  

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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