Добавил:

Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.

Вуз:

Московский государственный индустриальный университет

Предмет:

[НЕСОРТИРОВАННОЕ]

Файл:

basic mathematics for college students.pdf

Скачиваний:

147

Добавлен:

10.06.2015

Размер:

15.55 Mб

Скачать

☆

<<< < Предыдущая 21 22 23 24 25 26 27 28 29 30 31 3233 / 6733 34 35 36 37 38 39 40 41 42 43 44 45 > Следующая >>>

368	Chapter 4 Decimals

THINK IT THROUGH GPA

“In considering all of the factors that are important to employers as they recruit students in colleges and universities nationwide, college major, grade point average, and work-related experience usually rise to the top of the list.”

Mary D. Feduccia, Ph.D., Career Services Director, Louisiana State University

A grade point average (GPA) is a weighted average based on the grades received and the number of units (credit hours) taken. A GPA for one semester (or term) is deﬁned as

the quotient of the sum of the grade points earned for each class and the sum of the number of units taken. The number of grade points earned for a class is the product of the number of units assigned to the class and the value of the grade received in the class.

1.Use the table of grade values below to compute the GPA for the student whose semester grade report is shown. Round to the nearest hundredth.

Grade Value

F 0

Class	Units	Grade

Geology	4	C
Algebra	5	A
Psychology	3	C
Spanish	2	B

2.If you were enrolled in school last semester (or term), list the classes taken, units assigned, and grades received like those shown in the grade report above. Then calculate your GPA.

ANSWERS TO SELF CHECKS
ANSWERS TO SELF CHECKS
1.	5.2	2. 3.17		3. 5.35	4.	0.93 5.	14.24 6. 6,300	70 630 7 90
7.	a.	7.213	b.	0.00107	c.	194,407	8. a. 6.62 b.	239 9. 1.107 10. 5.5
11. 36 slices			12. 2.747 million visitors

S E C T I O N 4.4 STUDY SET

VOCABULARY

Fill in the blanks.

1.In the division problem shown below, label the dividend, the divisor, and the quotient.

				3.17
				5

					15.85

2.To perform the division 2.7 9.45, we move the decimal point of the divisor so that it becomes the

number 27.

CONCEPTS

3.A decimal point is missing in each of the following quotients. Write a decimal point in the proper position.

a.	526		b.	0008
	4			3
	4	21.04		3	0.024

4.a. How many places to the right must we move the decimal point in 6.14 so that it becomes a whole number?

b.When the decimal point in 49.8 is moved three places to the right, what is the resulting number?

5.Move the decimal point in the divisor and the dividend the same number of places so that the divisor becomes a whole number. You do not have to ﬁnd the quotient.

a.1.3 10.66

b.3.71 16.695

6.Fill in the blanks: To divide with a decimal divisor,


write the problem in		division form. Move the
decimal point of the divisor so that it becomes a
	number. Then move the decimal point of the
dividend the same number of places to the				.
Write the decimal point in the quotient directly
	the decimal point in the dividend and divide
as working with whole			.

7. To perform the division 7.8 14.562, the decimal points in the divisor and dividend are moved 1 place to the

right. This is equivalent to multiplying 14.562 by what

7.8

form of 1?

8.Use multiplication to check the following division. Is the result correct?

1.9170.9 2.13

9.When rounding a decimal to the hundredths column, to what other column must we look at ﬁrst?

10.a. When 9.545 is divided by 10, is the answer smaller or larger than 9.545?

b.When 9.545 is divided by 0.1, is the answer smaller or larger than 9.545?

11.Fill in the blanks.

a.To ﬁnd the quotient of a decimal and 10, 100, 1,000, and so on, move the decimal point to the

the same number of places as there are zeros in the power of 10.

b.To ﬁnd the quotient of a decimal and 0.1, 0.01, 0.001, and so on, move the decimal point to the

the same number of decimal places as there are in the power of 10.

12.Determine whether the sign of each result is positive or negative. You do not have to ﬁnd the quotient.

a.15.25 ( 0.5)

25.92

3.2

NOTATION

13.Explain what the red arrows are illustrating in the division problem below.

467 3208.7

4.4 Dividing Decimals

369

14.The division shown below is not ﬁnished. Why was the red 0 written after the 7 in the dividend?

2.3

2 4.70

4 0 7

6 1

GUIDED PRACTICE

Divide. Check the result. See Example 1.

15.	12.6 6					16.	40.8 8
	3						4
17.	3		27.6			18.	4	28.8

Divide. Check the result. See Example 2.
19.	98.21 23					20.	190.96 28
	37						32
21.	37			320.05		22.	32			125.12
Divide. Check the result. See Example 3.
23.	13.4 4					24.	38.3 5
	5						6
25.	5		22.8			26.	6		28.5
Divide. Check the result. See Example 4.
27.	0.1932					28.	0.2436

		0.42					0.29
		0.42					0.29
	0.29						0.58
29.	0.29				0.1131	30.	0.58				0.1566

Divide. Round the quotient to the nearest hundredth. Check the result. See Example 5.

11.83		16.43
31.		32.

0.6		0.9
17.09		13.07
33.		34.

0.7		0.6

Estimate each quotient. See Example 6.

35.289.842 72.1

36.284.254 91.4

37.383.76 7.8

38.348.84 5.7

39.3,883.284 48.12

40.5,556.521 67.89

41.6.1 15,819.74

42.9.2 19,460.76

Find each quotient. See Example 7.
43.	451.78 100	44.	991.02 100
45.	30.09	46.	27.07

	10,000		10,000
47.	1.25 0.1	48.	8.62 0.01
49.	545.2	50.	67.4

	0.001		0.001

370			Chapter 4							Decimals
Divide. See Example 8.
51.	110.336 12.8										52.	121.584 14.9
53.	91.304 ( 22.6)										54.	66.126 ( 32.1)
55.	20.3257										56.	48.8933

	0.001											0.001
	0.001											0.001
57.	0.003 ( 100)										58.	0.008 ( 100)
Evaluate each expression. See Example 9.
59.	2(0.614) 2.3854										60.	2(1.242) 0.8932

	0.2 0.9											0.4 0.8
	0.2 0.9											0.4 0.8
61.	5.409 3(1.8)										62.	1.674 5(0.222)

	(0.3)2											(0.1)2
	(0.3)2											(0.1)2
Evaluate each formula. See Example 10.
		d
63.	t					for d 211.75 and r 60.5
63.	t	r				for d 211.75 and r 60.5
64.	h			2A				for A 9.62 and b 3.7
64.	h							for A 9.62 and b 3.7
						b
65.	r		d				for d 219.375 and t 3.75

				t
66.	p				C			for C	14.4513 and d 4.6 (Round to the

					d

nearest hundredth.)

TRY IT YOURSELF

Perform the indicated operations. Round the result to the speciﬁed decimal place, when indicated.

67.	4.5		11.97	68.	4.1		14.637
69.	75.04			70.	22.32

	10				100
	8				4
71.		0.036		72.		0.073
	9				6
73.		2.889		74.		3.378
75.	3(0.2) 2(3.3)			76.	( 1.3)2 9.2
	30(0.4)2				2(0.2) 0.5

77.Divide 1.2202 by 0.01.

78.Divide 0.4531 by 0.001.

79.5.714 2.4 (nearest tenth)

80.21.21 3.8 (nearest tenth)

81.	39 ( 4)	82.	26 ( 8)
83.	7.8915 .00001	84.	23.025 0.0001
85.	0.0102	86.	0.0092

	0.017		0.023

87.12.243 0.9 (nearest hundredth)

88.13.441 0.6 (nearest hundredth)


89.	1,000		34.8	90.	10,000 678.9

91.	40.7(3 8.3)	(nearest hundredth)
91.	0.4 0.61	(nearest hundredth)
	0.4 0.61
92.	(0.5)2 (0.3)2		(nearest hundredth)
92.	0.005 0.1		(nearest hundredth)
	0.005 0.1
93.	Divide 0.25 by 1.6			94. Divide 1.2 by 0.64

APPLICATIONS

95.BUTCHER SHOPS A meat slicer trims 0.05-inch- thick pieces from a sausage. If the sausage is 14 inches long, how many slices are there in one sausage?

	96. ELECTRONICS The volume control	VOLUME
	on a computer is shown to the right. If	VOLUME
	on a computer is shown to the right. If	CONTROL
	the distance between the Low and High	Low
	settings is 21 cm, how far apart are the


	equally spaced volume settings?

97.COMPUTERS A computer can do an arithmetic calculation in 0.00003 second. How many of these calculations could it do in 60 seconds?

98. THE LOTTERY In December of High 2008, ﬁfteen city employees of Piqua,

Ohio, who had played the Mega Millions Lottery as a group, won the jackpot. They were awarded a total of $94.5 million. If the money was split equally, how much did each person receive?

(Source: pal-item.com)

99.SPRAY BOTTLES Each squeeze of the trigger of a spray bottle emits 0.017 ounce of liquid. How many squeezes are there in an 8.5-ounce bottle?

100.CAR LOANS See the loan statement below. How many more monthly payments must be made to pay off the loan?

American Finance Company		June

Monthly	Paid to date: $547.30
payment:	Paid to date: $547.30
payment:
$42.10	Loan balance: $631.50

101.HIKING Refer to the illustration below to determine how long it will take the person shown to complete the hike. Then determine at what time of the day she will complete the hike.

Departure

Arrival

A.M.

11	12	1		11	12	1
10		2		10	?	2
9		3	The hiker walks	9	?	3
8		4	2.5 miles	8		4
7	6	5	2.5 miles	7	6	5
	6		each hour.		6
			each hour.

Start	27.5-mile hike	Finish
	27.5-mile hike

102.HOURLY PAY The graph below shows the average hours worked and the average weekly earnings of U.S. production workers in manufacturing for the years 1998 and 2008. What did the average production worker in manufacturing earn per hour

a. in 1998?

b. in 2008?

U.S. Production Workers in Manufacturing

	800
	700		$710.70
	700
weekly earnings ($)			42
	600	$556.83		per worked hours
		$556.83
	500	41.4 hr	41.2 hr
	500		41.2 hr		Average
	400		41
	400
	300
Average	300			week
	200		40
	200
	100
	0		39
		1998	2008
			Year

Source: U.S. Department of Labor Statistic

103.TRAVEL The illustration shows the annual number of person-trips of 50 miles or more (one way) for the years 2002–2007, as estimated by the Travel Industry Association of America. Find the average number of trips per year for this period of time.

U.S. Domestic Leisure Travel (in millions of person-trips of 50 mi or more, one way)

1,600
1,500		1,440.4	1,482.5	1,491.8	1,510.4
1,500
1,407.1
1,407.1
1,400
1,300	1,388.2
1,300
1,200
2002	2003	2004	2005	2006	2007
		Year

Source: U.S. Travel Association

104.OIL WELLS Geologists have mapped out the types of soil through which engineers must drill to reach an oil deposit. See the illustration below.

	Surface
Silt	0.68 mi
Rock	0.36 mi
Sand	0.44 mi
Oil

4.4 Dividing Decimals

371

a.How far below the surface is the oil deposit?

b.What is the average depth that must be drilled each week if the drilling is to be a four-week project?

105.REFLEXES An online reaction time test is shown below. When the stop light changes from red to green, the participant is to immediately click on the large green button. The program then displays the participant’s reaction time in the table. After the participant takes the test ﬁve times, the average reaction time is found. Determine the average reaction time for the results shown

below.

Test	Reaction Time	The stoplight	The button
Number	(in seconds)	to watch.	to click.
1	0.219
2	0.233
2	0.233			Click
3	0.204			here
				on
4	0.297			on
4	0.297			green
5	0.202			light
5	0.202

AVG.	?

106.INDY 500 Driver Scott Dixon, of New Zealand, had the fastest average qualifying speed for the 2008 Indianapolis 500-mile race. This earned him the pole position to begin the race. The speeds for each of his four qualifying laps are shown below. What was his average qualifying speed?

					Lap 1: 226.598 mph
					Lap 1: 226.598 mph
					Lap 2: 226.505 mph
					Lap 3: 226.303 mph
					Lap 4: 226.058 mph
					Lap 4: 226.058 mph

					(Source: indianapolismotorspeedway.com)
1
1
:2
:3

WRITING

107.Explain the process used to divide two numbers when both the divisor and the dividend are decimals. Give an example.

108.Explain why we must sometimes use rounding when we write the answer to a division problem.

109.The division 0.5 2.005 is equivalent to 5 20.05 . Explain what equivalent means in this case.

110.In 3 0.7, why can additional zeros be placed to the right of 0.7 without affecting the result?

111.Explain how to estimate the following quotient: 0.75 2.415

<<< < Предыдущая 21 22 23 24 25 26 27 28 29 30 31 3233 / 6733 34 35 36 37 38 39 40 41 42 43 44 45 > Следующая >>>

Соседние файлы в предмете [НЕСОРТИРОВАННОЕ]

#
10.12.2018408.58 Кб6antikrizisnoe-upravlenie.doc
#
18.12.2018108.03 Кб6ARHITYeKTURA.doc
#
10.06.20158.32 Mб302aswath_damodaran-investment_philosophies_2012.pdf
#
10.06.201582.94 Кб7audit_risk.doc
#
10.06.20154.17 Mб5BallotingApplicationDocs-SIMSUsersGuide.pdf
#
10.06.201515.55 Mб147basic mathematics for college students.pdf
#
10.06.2015901.06 Кб40Bazy_dannykh_i_znanii_UP_SHirokov_L.A._2000.pdf
#
29.03.20162.45 Mб35Bernd_Fon_Vittenburg_-_Shakh_planete_Zemlya.pdf
#
10.06.201561.93 Кб44bezopasnost.docx
#
10.06.20152.89 Mб85bibliofond_ru_604241.docx
#
10.06.20152.1 Mб30blind_watchmaker.pdf