This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Stat 119 Name:
quiz éiB Red id: t. (i pointﬂf P(A) = 0.20 and P(B) = 0.10, what is PM u E) if A and B are independent? A. 0.30 B. 0.02 c. 0.32 1: 0.28
Mag so eteeﬁe featherek A E m m nswer:
attest... rewrite iota as
2. {1 point) In order to determine the effects of a healthy diet and exercise on cholesterol
levels, 100 randomiy seiected subjects are assigned to one of three diet groups: 1 serving
of vegetables, 3 servings of vegetables, or 5 serviags of vegetahies, and one of three
exercise groups: no exercise, 30 minutes per day. or 60 minutes per day. The subjects’ cholesteroi is measured at the beginning of the study and after 3 months. How many
treatments are there in this experiment? g x 3 g; a A6 (3.3 D.2 Answer (1 point) Coffee stations in offices often just ask users to ieave money in a jar to pay for
their coffee, bet some peopie cheat. Researchers replaced a picture of ﬂowers behind the
office coffee table with. a picture of staring eyes. They found a statistically signiﬁcant
increase in the average contribution when people feit they were being watched (even
though the eyes were not real). The term statistically significant means: A. The increase in contributions was smart! enough that it conic! be attributed to chance.
The increase in contributions was large and due to chance The increase in contributions was large enough that it would be unlikeiy to occur by chance
D. The coffee drinkers preferred the picture of staring eyes.
4. (1 point) Reai estate ads soggest that 64% of homes for sale have garages, 21% have
swimming pools, and 68% have at least one of these two features. What is the probabiiity
that a home for saie has both a garage and a swimming pool? @313. § kg. :33, i A. 0.1428 8. 0.4352 E D. 0.85 13.0.1344 p (5" ‘3 P}? ° 5 3
see. as; ing at htﬁ’o?
3e was?) a ' i?” Answer
5. (l pnt) Which of the following is aiways tree? Poi m 13) «1 P(B n A)
a. P(AB):P(BA) if j
c. P(AUB) = P(A)+P(B) K estate if as 959m?
D. If A and B are independent, then they are aiso disjoint. x Answer 3E UJ Answer ﬁxes fishes“ Wﬁaﬁﬁgiessf Use the foilowing information to answer Questions 6‘9
A survey of the members of a iocal YMCA indicates that 65% use the running track (event R), 45% use the swimming pool (event S), and 5% use neither.
6. (2 points) What is the probability that a randomly selected member uses both the i001 gggeé‘g; image 3%? :3 “ﬁg? ﬁvéﬁg W 9 §= iﬁ 3% 2% $5223 m as we s is? w ﬁis 7. (2 points) Fill in all 4 areas of the Venn diagram below R
' " as as 8. (2 points) What is the probability that a randomly selected member uses only the track? 9. {1 point) Is using the running track independent of using the swimming pool? Explain
using V:robabiiities caiculated from the information above. Pt {as 3% ersz we at tesS’XeQ Si HM Hawaii: gﬁ Use the following information to answer questions 1011 In a sales effectiveness seminar, a group of sales representatives tried two approaches to selling a
customer a new car: the aggressive approach and the passive approach. A record was kept for a
sample of 1100 customers. E Sales approach 1 Sale No Sale Total Aggressive l 270 l 310 i580 1
Passive 1 406 £14 1 520 1
Total I676 424 l 1100 1 10. (1 points) Given that a randomly seiected customer was subjected to the aggressive
approach, what is the%bability a sale Pea m is an aggressive approach was used? + see, u 3%;
u as use has $9 s ii :(gf‘: awake were? mg Use the following information to answer problems 1214
A large ﬁrm offers its employees one of two pension plans, A or 8. Records Show that 70% choose plan A. 60% of ihose who chose plan A are married, and 45% of those who choose plan B
are married Let M be the event: Ehat the employee is married.
i2. (2 points) Clearly draw and label a tree diagram for this scenario using the correct notation and numerical values:
?5 egg ﬁfﬁlle a in? 1 g {M l a‘l .2: l e E3. (2 points) What is the probability {hat a randomly selectecl employee is not married? 95W) a; Pregame? an: weenie} eel. z? “5% so? a: “Leila
Answer: 14. (2 points) If a randomly selected employee is not married. what is the probability the
employee chose pension plan B? WW? 2 :: g a . We :5
Answer: are
P(AC)=1—P(A) P(AUB)=P(A)+P(B)WP(AOB) P(AUB):P(A)+P(B) P(Ar‘\B)mP(A)P(B) P(AﬂB):P(A]B)P(B) ...
View
Full Document
 Spring '07
 Helen
 Statistics, randomly selected member

Click to edit the document details