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59 . Write the symbols for the probability that the student is an education major, given that the student is male.

3.2: independent and mutually exclusive events

60 . Events A and B are independent.
If P ( A ) = 0.3 and P ( B ) = 0.5, find P ( A AND B ).

61 . C and D are mutually exclusive events.
If P ( C ) = 0.18 and P ( D ) = 0.03, find P ( C OR D ).

3.3: two basic rules of probability

62 . In a high school graduating class of 300, 200 students are going to college, 40 are planning to work full-time, and 80 are taking a gap year. Are these events mutually exclusive?

Use the following information to answer the next two exercises. An archer hits the center of the target (the bullseye) 70 percent of the time. However, she is a streak shooter, and if she hits the center on one shot, her probability of hitting it on the shot immediately following is 0.85. Written in probability notation:
P ( A ) = P ( B ) = P (hitting the center on one shot) = 0.70
P ( B | A ) = P(hitting the center on a second shot, given that she hit it on the first) = 0.85

63 . Calculate the probability that she will hit the center of the target on two consecutive shots.

64 . Are P ( A ) and P ( B ) independent in this example?

3.4: contingency tables

Use the following information to answer the next three exercises. The following contingency table displays the number of students who report studying at least 15 hours per week, and how many made the honor roll in the past semester.

Honor roll No honor roll Total
Study at least 15 hours/week 200
Study less than 15 hours/week 125 193
Total 1,000

65 . Complete the table.

66 . Find P (honor roll|study at least 15 hours per week).

67 . What is the probability a student studies less than 15 hours per week?

68 . Are the events “study at least 15 hours per week” and “makes the honor roll” independent? Justify your answer numerically.

3.5: tree and venn diagrams

69 . At a high school, some students play on the tennis team, some play on the soccer team, but neither plays both tennis and soccer. Draw a Venn diagram illustrating this.

70 . At a high school, some students play tennis, some play soccer, and some play both. Draw a Venn diagram illustrating this.

Practice test 1 solutions

1.1: definitions of statistics, probability, and key terms

1 .

  1. population: all the shopping visits by all the store’s customers
  2. sample: the 1,000 visits drawn for the study
  3. parameter: the average expenditure on produce per visit by all the store’s customers
  4. statistic: the average expenditure on produce per visit by the sample of 1,000
  5. variable: the expenditure on produce for each visit
  6. data: the dollar amounts spent on produce; for instance, $15.40, $11.53, etc

2 . c

3 . d

1.2: data, sampling, and variation in data and sampling

4 . d

5 . c

6 . Answers will vary.
Sample Answer: Any solution in which you use data from the entire population is acceptable. For instance, a professor might calculate the average exam score for her class: because the scores of all members of the class were used in the calculation, the average is a parameter.

7 . b

8 . a

9 .

# of years Frequency Relative Frequency Cumulative Relative Frequency
<5 25 0.25 0.25
5–10 30 0.30 0.55
>10 45 0.45 1.00

Questions & Answers

Ayele, K., 2003. Introductory Economics, 3rd ed., Addis Ababa.
Widad Reply
can you send the book attached ?
Ariel
?
Ariel
What is economics
Widad Reply
the study of how humans make choices under conditions of scarcity
AI-Robot
U(x,y) = (x×y)1/2 find mu of x for y
Desalegn Reply
U(x,y) = (x×y)1/2 find mu of x for y
Desalegn
what is ecnomics
Jan Reply
this is the study of how the society manages it's scarce resources
Belonwu
what is macroeconomic
John Reply
macroeconomic is the branch of economics which studies actions, scale, activities and behaviour of the aggregate economy as a whole.
husaini
etc
husaini
difference between firm and industry
husaini Reply
what's the difference between a firm and an industry
Abdul
firm is the unit which transform inputs to output where as industry contain combination of firms with similar production 😅😅
Abdulraufu
Suppose the demand function that a firm faces shifted from Qd  120 3P to Qd  90  3P and the supply function has shifted from QS  20  2P to QS 10  2P . a) Find the effect of this change on price and quantity. b) Which of the changes in demand and supply is higher?
Toofiq Reply
explain standard reason why economic is a science
innocent Reply
factors influencing supply
Petrus Reply
what is economic.
Milan Reply
scares means__________________ends resources. unlimited
Jan
economics is a science that studies human behaviour as a relationship b/w ends and scares means which have alternative uses
Jan
calculate the profit maximizing for demand and supply
Zarshad Reply
Why qualify 28 supplies
Milan
what are explicit costs
Nomsa Reply
out-of-pocket costs for a firm, for example, payments for wages and salaries, rent, or materials
AI-Robot
concepts of supply in microeconomics
David Reply
economic overview notes
Amahle Reply
identify a demand and a supply curve
Salome Reply
i don't know
Parul
there's a difference
Aryan
Demand curve shows that how supply and others conditions affect on demand of a particular thing and what percent demand increase whith increase of supply of goods
Israr
Hi Sir please how do u calculate Cross elastic demand and income elastic demand?
Abari
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Source:  OpenStax, Introductory statistics. OpenStax CNX. May 06, 2016 Download for free at http://legacy.cnx.org/content/col11562/1.18
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