# The population of a city has been decreasing exponentially since 1990. In 1990, the population was 1,000,000. In 2010, the population was 560,000. If t represents time in years since 1990, which of the following equations best models the decay

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1. ## pre calc

The population of a Midwestern city decays exponentially. If the population decreased from 900,000 to 800,000 from 2003 to 2005, what will be the population in 2008? Please help I got 670,422 and the computer marked it round i then tried rounding it to

2. ## MATH

4. The population of a small town is modelled by the function p(t)= 20(4t+3)/2t+5 , where P(t) is the population, in thousands, and t is time, in years, since the start of 1990. a) Is the population currently increasing or decreasing? Justify your answer.

3. ## Math

The population of a southern city follows the exponential law. If the population doubled in size over 13 months and the current population is 30,000 what will the population be in 5 years from now?

4. ## Math

he world population at the beginning of 1990 was 5.3 billion. Assume that the population continues to grow at the rate of approximately 2%/year and find the function Q(t) that expresses the world population (in billions) as a function of time t (in years),

5. ## Math

The population of Winnemucca Nevada can be modeled by P=6191(1.04)^t where t is the number of years since 1990. What was the population in 1990? By what percent did the population increase by each year?

6. ## Math

The population of a city has been decreasing exponentially since 1990. In 1990, the population was 1,000,000. In 2010, the population was 560,000. If t represents time in years since 1990, which of the following equations best models the decay of the

7. ## Algebra

a. Do some research and find a city that has experienced population growth. Determine its population on January 1st of a certain year. Write an exponential function to represent the city’s population, y, based on the number of years that pass, x after a

8. ## algebra

The population of a city in 2005 was 18,000. By 2010, the city’s population had grown to 45,000. Economists have determined that the population growth follows an exponential model. If they are correct, what is the projected population for 2015?

9. ## Calculus

The population of a region is growing exponentially. There were 40 million people in 1980 (when t=0) and 50 million people in 1990. Find an exponential model for the population (in millions of people) at any time t, in years after 1980. P(t)= Predicted

10. ## Pre calc

The population of a Midwestern city decays exponentially. If the population decreased from 900,000 to 800,000 from 2003 to 2005, what will be the population in 2008? I thought it was 7542 but it is wrong can someone please help me thank you

11. ## pre calc

The population of a Midwestern city decays exponentially. If the population decreased from 900,000 to 800,000 from 2003 to 2005, what will be the population in 2008? Please help I got 670,422 and the computer marked it wrong i then tried rounding it to

12. ## Math - I really need help, please.

A town has a population of 8400 i 1990. Fifteen years later, it's population grew to 12500. Determine the average annual growth rate of this town's population. I really don't understand this problem. I've been going at it for hours and all I've come to is

the population of a town is decreasing at a rate of 1.8% per year. The current population of the own in 12000. a)write and equation that models the population of the town b)how long will it take for the population to decline to one quarter of its current

14. ## Science

This graph shows the changes in two populations of herbivores in a grassy field. In the y axis it says number of organisms in the x- axis it says Time In the graph A is decreasing , B is increasing, At first they were steady then slightly A decreased and B

15. ## Math1

The population of Winnemucca, Nevada , can be modeled by P=6191(1.040^t where t is the number of years since 1990. What was the population in 1990? By what percent did the population increase by each year?

16. ## Math

The population of a city has been decreasing exponentially since 1990. In 1990, the population was 1,000,000. In 2010, the population was 560,000. If t represents time in years since 1990, which of the following equations best models the decay of the

17. ## Math

The population, P (in thousands), of a town can be modeled by P= 2|t-6|+4, where t=0 represents 1990. During which two years does the town have a population of 8000? Can someone show me the steps to this problem?

18. ## calculus

I solved this problem, can someone check it to make sure I did it right. There are two parts to this intrepation and estimate of the value. Let C(t) be the total value of the US currency (coins and banknotes) in circulation at time, t. The table gives

19. ## math

The population of a small town is modelled by the function p(t)= 20(4t+3)/2t+5 , where P(t) is the population, in thousands, and t is time, in years, since the start of 1990. a) Is the population currently increasing or decreasing? Justify your answer. b)

20. ## math

The population p of a city is given by p=240,360e^0.012t where t=0 represents 1990. According to this model, when will the population reach 275,000? I know that you have to sustitute 275,000 into the p but I do not know how to solve it.

21. ## Math

The population in a 55 square mile city, City A, is 44,000. A neighboring city, City B, measures 65 square miles and has 48,750 citizens. Determine which city has a greater population density and by what percentage its population density is greater than

22. ## Science help urgent :/

What has been the general trend in human population growth? A.) The human population has decreased. b.) The human population has remained constant. C.) The human population has grown exponentially. d.) The human population has increased and then decreased

23. ## MATH

4. The population of a small town is modelled by the function p(t)= 20(4t+3)/2t+5 , where P(t) is the population, in thousands, and t is time, in years, since the start of 1990. a) Is the population currently increasing or decreasing? Justify your answer.

24. ## Calculus

for population in billions, where t is years since 1990: N(t) = 41/1+11 e^−0.1 t (b) According to this model, when will the earth's population reach 20.5 billion? During the year . How about 40.9 billion? During the year .

25. ## calculus

Bacterial Population: A bacterial colony is estimated to have a population of P(t)=(24t+10)/(t^2+1) Million t hours after the introduction or a toxin. At what rate is the population changing in 1 hour after the toxin is introduced (t=1)? Is the population

26. ## science

How has the human population changed during the last 50 years? A: The human population has increased exponentially. B: The human population has decreased exponentially. C: The human population did not change. D:The human population increased and then

27. ## calculus

The population of a country was 8.4 million people in 2000. Three years later, the population of the same nation was 9.3 million people. Assuming that population is growing exponentially, what is the projected population (rounded to one-tenth of a million)

28. ## Math

From 1980 to 1990 the population of London increased by 6%. From 1990 to 2000, the population of the city decrease by 3%. What was the overall percentage change in the population of London from 1980 to 2000?

29. ## Applied Calculus

The world population at the beginning of 1990 was 5.3 billion. Assume that the population continues to grow at the rate of approximately 2%/year and find the function Q(t) that expresses the world population (in billions) as a function of time t (in

30. ## Math

The population of a town double every 10 years from 1960 to 1990.what was the percent increase in population during this time

31. ## math

the population of a town was 50000 in 1990. in 2000 it rose to 80000. find the percentage increase of the population.

32. ## math, calculus

Assume that a population was 853 when t=0, and 3 years later it became 2314. Assuming the population grows exponentially, write a formula for the size of the population in t years: Population = What is the population when t = 12?:

33. ## pre calc

population of city has varied considederably in recent years. the data it the relates the pollution P to time t, in years, where t=0 correponds to 1990. use a quadratic function fitted to the data to predict the population in 2000 data: year,t population P

34. ## Math

The population, P (in thousands), of a town can be modeled by P= 2|t-6|+4, where t=0 represents 1990. During which two years does the town have a population of 8000? Can someone show me the steps to this problem?

35. ## math

The population of a city in 2005 was 18,000. By 2010, the city’s population had grown to 32,800. If the population growth follows a linear model, what is the projected population for 2015?

36. ## algebra

neil was growing a culture of bacteria for a biology experiment. he noticed that the population doubled after 90 minutes. if the population grows exponentially, how many times the original population will there be after six hours?

37. ## Science

What has been the general trend in human population growth? A. The Human Population has decreased. B. The Human Population has remained constant. C. The Human Population has grown exponentially. D. The Human Population has increased and then decreased

38. ## math

The population of a southern city follows the exponential law. If the population doubled in size over 28 months and the current population is 70 comma 000​, what will the population be 4 years from​ now?

39. ## Science

what has been the general trend in human population growth? A(the human population has decreased B(the human population has remained constant C(the human population has grown exponentially** D(the human population has increased and then decreased

40. ## Math

The population, in millions, of a city t years after 2000 is given by the function P(t) = 2.9 - 0.008t. Which statement is true? A. The population is increasing by 8,000 people per year. B. The population is decreasing by 8,000 people per year. C. They

41. ## Math

From 1990 to 2006, the population, p (in millions), of a large city can be modeled by p = 1.1(1.05)t, where t is the number of years since 1990.

42. ## algebra

In 1990, the population of Africa was 643 million and by 2000 it had grown to 813 million. a.) Use the exponential growth model A=A0 e^kt, in which t is the number of years after 1990, to find the exponential growth function that models the data. b.) By

43. ## Algebra

These data represent the population of a certain city. Year Population(in thousands) 1950 18 1960 23 1970 29 1980 32 1990 38 2000 42 Use the line graph to predict the population in the year 2010 I recommend graphing the points, draw a best fit line, then

The population of a small town is modeled by the function p(t)=20(4t+3)/2t+5, where P(t) is the population, in thousands, and t is time, in years, since the start of 1990. The town will need its own transit system if the population exceeds 50,000. Will the

45. ## Math 11u

A town has a population of 8400 in 1990. Fifteen years later, it's population grew to 125,000. Determine the average annual growth rate of this town's population. Round to the nearest tenth of a percent.

46. ## Algebra 1B Chapter 10

I'm reclassified but I'm still a 10th grader and the only class I need to take is Algebra1B So here's the problem. I'm 1990, the town of Belgrade, Montana, had a popuof of 3422. For each of the next 8 years, the population increased by 4.9% per year. a.

47. ## Math

Based on census data, the population of Freedonia is modeled by the function P(t)= 310t^2+25474 people, where t represents the number of years after 1990. Use this function to determine how fast the population was increasing at the end of the year 1995.

48. ## working with data

the table below shows the population of New London County, Ct from 1950 to 2000. year population 1950 145,000 1960 186,000 1970 230,000 1980 238,000 1990 255,000 2000 259,000 -how do i make a scatter plot of the data? -predict the population in 2010.

49. ## college algebra

Median family income in country x between 1990 and 1999 can be modeled by f(x)=1144.7(x-1990)+35,834 where x is the year. Determine the median income was \$42,303. I did it this way don't know if it's right f(x)=1144.7(x-1990)+35,834 42,303-35,834 = 1144.7

50. ## algebra

neil was growin a culture of a bacteria for biology experiement. he noticed that the population doubled after 90 minutes. if the population grows exponentially, how many times the original population will there be after 6 hours?

51. ## Precalculus

The population of the US in 1850 was 23191876. In 1900, the population was 62947714. a. assuming that the population grew exponentially, compute the grownth constant. b. assuming continued growth at a constant rate, predict the population in 1950.

52. ## precalculus

the population of a country is 65 millions if it grows exponentially in a rate of 1.5% annual 1.-calculate the estimate population in 12 years 2.-when the population increases 4 times could somebody please explain me this kind of problems where you need to

53. ## algebra connections

8. The population of Grand City in 1990 was 5,250. Assume the population is increasing at 2.5% per year. What was the population in Grand City in 2010 (round answer to the nearest person)?

54. ## Pre-Calc

You know the population of your nation was 151 million in 1990 and 173 million in 2000. Use the model f(t) = P e^rt to model your nation’s population t years after 1990. Using the correct rate of population growth, predict the year in which your

55. ## Geometry

From 1989 to 1990, the population of Nevada increased by 1.59 × 105, and that of Maine increased by 28000. In 1990, the population of Nevada was 1206152, and that of Maine was 1233223. If the populations of the two states continue to increase at the same

56. ## math

In 1980, the population of a certain country was about 161 000. since then the population has decreased about 1% per year. a. find an equation to model the population since 1980 b. estimate the population in 1990 c. suppose the current trend continues.

57. ## Precalculus

The Population of a small town is slowly decreasing, in 1990 there were 67,450 living in the city limits. Three years later there were 63,893, three years after that there were 60,524. Write an equation to model this situation?

58. ## mathematics

a town has a population of 8400 in 1990. Fifteen years later, it's population had grown to 12 500. Assuming that the population continues to grow at the same exponential rate, when will the population reach 20 000? Please help im trying to answer this

The U.S. population in 1990 was approximately 250 million, and the average growth rate for the past 30 years gives a doubling time of 66 years. The above formula for the United States then becomes P (in millions) = 250 times 2( y-1990)/66 What will the

60. ## Math

The population of Bumpton increased by 10% from 1980 to 1990 and decreased by 10% from 1990 to 2000 what is the net percent change in the population on Bumpton from 1980 to 2000 ?

61. ## algebra

A town has a population of 8400 in 1990. Fifteen years later, its population grew to 12500. Determine the average annual growth rate of this town's population. How do i solve this using applications of exponential functions?

62. ## MATH

A table of the U.S. population in millions indicated in 1960 the population was 181 million, in 1970 the population was 205 million, in 1980 the population was 228 million, and in 1990, the population was 250 million. Describe the context behind how the

63. ## Algerbra

The U.S. population in 1990 was approximately 250 million, and the average growth rate for the past 30 years gives a doubling time of 66 years. The above formula for the United States then becomes P (in millions)= 250 x 2( y-1990)/66 1.What was the

64. ## Math AP Calc

The population of New Hampshire was 1 million in 1990. It doubles every 25 years. Estimate the population in 1996.

65. ## Math

The population of New Hampshire was 1 million in 1990. It doubles every 25 years. Estimate the population in 1996.

66. ## Math 11u

A town has a population of 8400 in 1990. Fifteen years later, it's population grew to 12,500. Determine the average annual growth rate of this town's population. Round to the nearest tenth of a percent. (the answer in the book is approx.2.7) thank you for

67. ## Math

In 1990, the population of Cheyenne, Wyoming, was 73,142. By 2000, the population had increased to 81,607. Write and solve an equation to find, the increase in Cheyenne’s population from 1990 to 2000. Mercury’s surface temperature has a range of 600

68. ## Math

THe population of Anytown in 1960 was 1,576,230. In 1990 the population was 892,560. Find the percent change. AM REALLY CONFUSED PLEASE HElp

69. ## Algebra

Since populations are continuously changing based on their immediate previous state, the Pert formula can be used to quickly estimate near future growth (or decay). Assume that the 1990 census for a city of 800,000 reveals an annual increase of 2.3%,

70. ## pre calculus

According to projections by a organization of​ countries, the population of a certain country​ (in billions) can be approximated by the following function where x=0 corresponds to the year 1990. In what year will the country reach its maximum​

71. ## Math

Use the following information regarding the farm population(in millions of persons)from 1945-1990. Year 1945 1990 Millions of persons 24.3 4.4 a. Write a linear model for the farm population,y,in millions of persons.Let x=0 represent 1945. b. Use the

72. ## Math

Use the following information regarding the farm population(in millions of persons)from 1945 to 1990. Year 1945 1990 Millions of Persons 24.3 4.4 a. Write a linear model for the farm population, y, in millions of persons. Let X=0 represent 1945. b. Use the

73. ## Algebra 1B Chapter 10

I'm reclassified but I'm still a 10th grader and the only class I need to take is Algebra1B So here's the problem. I'm 1990, the town of Belgrade, Montana, had a popuof of 3422. For each of the next 8 years, the population increased by 4.9% per year. a.

74. ## MATH

Use the following information regarding the farm population(in millions of persons)from 1945 to 1990. Year 1945(24.3 millions of persons), 1990(4.4 Millions of Persons). a. Write a linear model for the farm population, y, in millions of persons. Let X=0

75. ## Algebra

the population P (in 1000s) of a town can be modeled by P = 2 absolute value t-5 +6, where t = 0 represent 1990. During which two years does the town have a population of 12,000?

76. ## Algebra II

The population, P (in 100's), of a town can be modeled y P = 2 /t -5/ = 6, where t = 0 represents 1990. During whuch two years does the town have a population of 12,000.?

77. ## math

Thank goodness for this site! Two questions: first: in the 1990 U.S. census, the final count was 248,709,873 people. The general population is estimated to have been undercounted by 1.8%, that is, only 98.2% of the people were counted. If this were the

78. ## math 117/algebra

The US population 1990 was approximately 250 million, and the average growth rate for the past 30 years gives a doubling time of 66 years. The above formula for the US then becomes P(in millions) = 250 x 1(y - 1990)/66 (1) What will the population of the

79. ## Algebra

The town of Appleville recorded the following dates and populations. YEAR POPULATION (in thousands) 1980 51.5 1985 53 1990 56 1995 62 Estimate the approximate population of Appleville in 1988 by finding an equation and then substituting.

80. ## Pre Calculus

The population of a city is 127,000 and is decreasing by 2.4% each year. a. What will the population be in 10 years? b. Find when the population will be 95,000

81. ## Algebra

The town of appleville recorded the following dates and populations. YEAR POPULATION 1985 51.5 1985 53 1990 56 1995 62 Estimate the approximate population of Appleville in 1988 by finding an equation and then substituting. HELP!!!

82. ## pre calc

The following polynomial approximates the rabbit population in a particular area.? R(x)= -0.121x^5+2.952x^4+3500, where x is the number of years frm 1975. use a graphing calculator to describe the rabbit population from the rears 1975 to 1990. how do you

83. ## college algebra

Median family income in country x between 1990 and 1999 can be modeled by f(x)=1144.7(x-1990)+35,834 where x is the year. Determine the median income was \$42,303. I did it this way don't know if it's right f(x)=1144.7(x-1990)+35,834 42,303-35,834 = 1144.7

84. ## Algebra 1- 8th Grade

According to the 1990 Census, the population of the United States was 2.49 x 10^8. The cost of taking the census in 1990 was 2.6 x 10^9 dollars. How much did the census cost per person in the United States?

85. ## Math question

I have this graph with the numbers Year population (thousands) 1950 132 1960 187 1970 254 1980 346 1990 466 2000 657 I need help in analyzing this data so that I can determine the year in which the population will reach 1,000,000 people. how would i make

86. ## Math

According to the U.S Bureau of Census in the year 1850 the population of the US was 23,191,876 in 1900 the population was 62,947,714 A. Assuming that the population grew exponentially during the period compute the growth constant k. B. Assuming continued

87. ## math

P=347e^.023t, where t is the number of years after 1990. According to the model, in what year will the population reach 1000?

88. ## math

P=347e^.023t, where t is the number of years after 1990. Use the model to estimate the population in the year 2012.

89. ## math

The population of a southern city follows the exponential law. If the population doubled in size over 15 months and then current population is 40,000, what will the population be 4 years from now?

90. ## Precalculus

The population of a southern city follows the exponential law. If the population doubled over 20 months and the current population is 70,000, what will the population be 5 years from now

91. ## Math

In a favorable habitat and without natural predators, a population of reindeer is introduced to an island preserve. The reindeer population t years after their introduction in 1990 is given by . F(t)=-0.125t^5+3.125t^4+4000. Estimate the number of reindeer

92. ## science

what has been the general trend in human population growth? the human population has decreased the human population has remained constant the human population has grown exponentially the human population has increased the decreased significantly

93. ## RTC

The population of a southern city follows the exponential law. If the population doubled in size over 2929 months and the current population is 30 comma 00030,000​, what will the population be 33 years from​ now

94. ## Math

A deer population was measured to be 4000. Two years later , it was measured to be 4300. assume the population grows exponentially. A). Write an equation describe this situation. Find values of all constants. b) What will the population be four years after

95. ## Math

Population in a city was 8,60,000. In the next year, if it is increased by 14000 more one tenth of the previous population, the present population in the city?

96. ## Math/Precal

The size of a decreasing population is given by p(t)=P0(2)^-t/7 where p(t) represents the population as time, t, in years and p0 is the initial population what percent of the original population will be there after 10 years??

97. ## Math

The size of a decreasing population is given by p(t)=P0(2)^-t/7 where p(t) represents the population as time, t, in years and p0 is the initial population what percent of the original population will be there after 10 years??

98. ## Math

Jnuary 1, 1990 was a Monday. What day of the week was february 1, 1990 ?

99. ## math

Population of a certain country is decreasing by 0.8% every year. The population in 2015 is 9 million, what will be the population in 2016 is it 16200000

100. ## Alg. 2

In 2000 the deer population in NJ was 35000. In 2015 that number decreased to 21000. If the population can be modeled with an exponential decay model, what is the rate at which the population is decreasing?