In 1990, the population of the U. S. was about 250 million and was growing exponentially at a rate of about 1% per year. At this rate, in what year will the population have
doubled?

a. 2080
b. 2070
c. 2060
d. 2050

The correct answer is C.

Step-by-step explanation:

Giving the following information:

Present Value (PV)= 250 million

Future Value (FV)= 500 million

Growth rate (g)= 1% per year

First, we need to calculate the number of years required for the population to double:

n= ln(FV/PV) / ln(1+g)  

n= ln(500/250) / ln(1.01)

n= 69.66 = 70 years

It will take 70 years for the population to double.

step-by-step explanation:

a.   since the profit made in 2012 is equal to the profit made in 2014, the profit is           symmetric about the line y = 120,000.

step-by-step explanation:

given that megan owns a clothing boutique.

the profits of 2010, 11, are recorded and shown as follows:

years since     2010 0     1     2     3       4       5

profits made in 1000's   39       84     111     120   111     84

we find that profit gradually increases form 2010 to 2013 upto 120,   then starts decreasing.

the profits for 2012 and 2014 are the same while that of 2011 and 2015 are also the same.

this shows that there is symmetry about the line profit = 120000

hence answer is:

a.   since the profit made in 2012 is equal to the profit made in 2014, the profit is           symmetric about the line y = 120,000.

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rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500