University:
York University
Course:
MATH 1131 | Introduction to Statistics I
Academic year:

2022
Views:

56

Pages:

2
Author:

Niklas

LECTURE 16 Example twina. P(1):30%=0.3 sum up to 100% because these are the only twe P(F):70%=0.7 opsions P(H1): 50%-0.5 P(F11)-50%=0.5 tot 100% P(M/F) 25% 0.15 P(F) F) 25%-0.25 P(Mixed F)-50%= 0.5 }- tot 100% P(1/F)? P(1/F): P(1)-P(F11) ( 0.3) (0.5) 3140 10 2 43 6 13=0.46=46% P(F) 0.325 Example: Automobile sales incentive A car dealership knows from past experience that of the pe mes the to a salesperson wil eventually To increase the chances of success you propcac to offers fres dinner with a salesperson for al people who agree to listen to a complete sales presentation You know that some people will do anything for a free dinner even if they do not intend to purchase a car loveever, sure people would wther not sperada dinner with a car salesperson. Thus, you wish to on the flateness of P(C)=10%=0.1 The projet is acted for 6 montin, amd 40% of con din addition, of the ye P(DIC)=40%=0.4 P(DIC)=10%-0.1 a. Du peuple who accept the dinner lave a higher probability of purchasing a now car? b. What is the probability that a person who does not accept a free dinner will purchase a car? a.P(CID) P(C)P(DIC) (0.1) (0.6) 10.871 1 10 10 100 4 13 13 030730,+% > P(D) P(D) P(C)P(DIC)+P(C)P(D))(0.1) (0.4)+(0.9) (0.1) 아바마마 1 4 10 I 10 4-P(DIC) 4-0.450.6 100 13 100=013-13% b. P(сіб)- P(c)P(DIC) (0.1) (0.6) P(5) 0.87 1-(0)-4-0.13-0.87 100 84 6 10 10 2 29=0.07=%P(CID) Example who was the internet? Internet usage varies among millennials (adalts born between 1981 and 1985), gon X-ers (adults bom between 1965 and 1980) boomers (adults born between P(M)+30% 1946 and 1964), and the silent generation (adults born before 1946). P(x)=24% Anang bom between 1946 and 1996, Xers 27%, boomers 32%, and silent generation 11% comprise gen P(8)=32% Also, of the 91% of gan X-ers uses the Intemet, 855% of boomers use Internet, and 78% legereration ses Intermek P(S)=11% What percentage of intermet asers from these four groups are millennials? P(11H)=100% P(1/x)91% P(M11)= P(M)P(11M) (0.3)(1) 3 10000 (০.৭০১5) 10 94035 600 1807 0.33-33% P(1/8)-85% P(1/5)=78% (P(104)+P(inx)+P(108)+P(105) P(114)P(M)+P(1x) P(x)+P(118) P(B)+P(15)P(S) 91 2785 32 78 11 100 123 5000 9035 10000 + 1010000 3000+2457+2720+858 10000 88 100 100 0903590.35% Raudom variable X is a variable whose value is aim of a raudom phenomenon, that is, it is a well de fined out unknown number Probability distribution of a random variable x tells us what value x cou take and how to assign probabililies to those values P(x)=P(Xax) Ux There are two main types of raudom variable: DISCRETE, if it has a finite list of possible outcomes, aud CONTIN, if it can take any value in au interval D the sunser of tails on time coin D the number of defective terms in a sangre of 20 am torn a large shipment D the number of students attending the statistics class of a Moncay C the diday time of the airplane the weghta reborn C the length of a Skype cal to yser mather For continuous tudom variables we cau assign probabilities only to range of values, using a mathematical function, so that one could compute the probability for the event "today's high temperature will be between 25" aud 26" So we express the probability distribution in continuous space