9. art's grandfather is on a fixed income. which of the following is true?
a. inflation causes his purchasing power to go down
b. inflation causes his purchasing power to go up
c. inflation has no effect on his purchasing power
10. freaky flakes cost $1.78 last year. this year a box costs $2.59. what is the inflation rate, to the nearest tenth percent?
a. 44.1%
b. 45.5%
c. 46.8%
d. 47.3%
11. amy, a senior, bought a car last year so that she could drive to school on the days when she needed to stay after class for practice. she spent $155 last year for gas. this year she spent $195. disregarding other factors, what is the inflation rate?
a. 27.1%
b. 25.2%
c. 26.8%
d. 25.8%
12. if your annual income from a part-time job is $2,698 and the inflation rate is 4%, what is the purchasing power of your income?
a. $2498.03
b. $2428.03
c. $2590.08
d. $2678.01
13. bart had an income of $45,670 last year. if the inflation rate is 4.5%, what is his purchasing power?
a. $43,614.85
b. $43,924.95
c. $44,543.75
d. $44,998.15

(1) Option (a) is true  i.e inflation causes his purchasing power to go down.

(2)The inflation rate percentage is 45.5% .

Option (b) is correct .

(3) inflation rate percentage is 25.8% .

Option (d) is correct .

(4)Purchasing power is $ 2590.08 .

Option (c) is correct .

(5)Purchasing power is $ 43614.85.

Option (a) is correct .

Step-by-step explanation:

First part

As given

Art's grandfather is on a fixed income.

(As inflation rate is inversely proportional to purchasing power i.e if inflation rate increase than purchasing power decrease .)

Thus Option (a) is true .

Second part

Formula

Where

Change in cost =  Cost this year - Cost last year

As given

Freaky Flakes cost $1.78 last year. This year a box costs $2.59

Change in cost = 2.59- 1.78

                         = $ 0.81

Putting all the values in the formula

Inflation rate percentage = 45.5%  (Approx)

Therefore  the inflation rate percentage is 45.5% .

Option (b) is correct .

Third part

As given

Amy, a senior, bought a car last year so that she could drive to school on the days when she needed to stay after class for practice.

Amy spent $155 last year for gas.

This year Amy spent $195.

Change in cost =  195 - 155

                         = $40

Inflation rate percentage = 25.8%

Therefore inflation rate percentage is 25.8% .

Option (d) is correct .

Fourth part

As given

 If your annual income from a part-time job is $2,698

If the inflation rate is 4% .

Thus

Purchasing percentage = ( 100 - 4 ) %

                                       = 96%

96 % is written in the decimal form

= 0.96

Let us assume that the purchasing power be x .

Than the equation becomes

x = 0.96 × 2698

x = $ 2590.08

Therefore purchasing power is $ 2590.08 .

Option (c) is correct .

Fifth part  

As given

Bart had an income of $45,670 last year.

If the inflation rate is 4.5% .

Thus

Purchasing percentage = ( 100 - 4.5 ) %

                                       = 95.5%

95.5 % is written in the decimal form

= 0.955

Let us assume that the purchasing power be x .

Than the equation becomes

x = 0.955 × 45670

x = $ 43614.85

Therefore purchasing power is $ 43614.85.

Option (a) is correct .

step-by-step explanation:

for exempl this   system of equations   y = x - 3

                                                                y = 2x - 5

look   the line : y = x -3     ( red)

                            the line : y = 2x -5 ( bleus)