Chapter 4.7, Problem 64E

(a)

To determine

To determine which country has greatest population

Answer to Problem 64E

China

Explanation of Solution

Given information:

Population of each country-

(a) China- $1.273\times {10}^9$

(b) Fiji- $844000$

(c) Iceland- $2.78\times {10}^5$

(d) Russia- $142300000$

Formula Used: Scientific Notation

Calculation:

To calculate, first change population of all countries in scientific notation & then compare-

(a) China- $1.273\times {10}^9$

(b) Fiji- $844000$ $=8.44\times {10}^5$

(c) Iceland- $2.78\times {10}^5$

(d) Russia- $142300000$ $=1.423\times {10}^8$

As, China has the highest exponent of 10 (which is 9)-China has the highest population.

Conclusion-

China

(b)

To determine

To determine which country has least population

Answer to Problem 64E

Iceland

Explanation of Solution

Given information:

Population of each country-

(e) China- $1.273\times {10}^9$

(f) Fiji- $844000$

(g) Iceland- $2.78\times {10}^5$

(h) Russia- $142300000$

Formula Used: Scientific Notation

Calculation:

To calculate, first change population of all countries in scientific notation & then compare-

(e) China- $1.273\times {10}^9$

(f) Fiji- $844000$ $=8.44\times {10}^5$

(g) Iceland- $2.78\times {10}^5$

(h) Russia- $142300000$ $=1.423\times {10}^8$

Here, both Iceland and Fiji has the lowest exponent for 10 (which is 5), so compare the two.

Since $2.78<8.44$ , Iceland has the least population.

Conclusion-

Iceland

(c)

To determine

To determine how many times the population of country in a) is greater than the population of country in b)

Answer to Problem 64E

  $=4.57\times {10}^3$

Explanation of Solution

Given information:

Population of each country-

(i) China- $1.273\times {10}^9$

(j) Fiji- $844000$

(k) Iceland- $2.78\times {10}^5$

(l) Russia- $142300000$

Formula Used: Quotient with Same Base

Calculation:

As already calculated in parts A) & B), China & Iceland has the greatest & least population.

To find how many times is China’s population greater than Iceland, divide the two

  $\frac{1.273\times {10}^9}{2.78\times {10}^5}$

On applying the Quotient Rule,

  $\frac{1.273\times {10}^{9-5}}{2.78}$

On dividing 1.273 &2.78 ,gives 0.457.

  $0.457\times {10}^4$

The correct scientific notation will be-

  $=4.57\times {10}^3$

Conclusion-

  $=4.57\times {10}^3$