Question

Week 7 1) The population from which a sample is drawn is: a) Always Normal in shape b) Bigger in size than the sample size (N is greater than ) c) A large number of subjects or people d) None of the above 2) The probability of 2 heads when we flip a coin twice is: a) 1 b).5 C) 25 d).75 e) Unknown 3) How many possible values of the variable "# of heads when a coin is flipped 4 times are there: a) 5 b) 4 c) 1 d) 25 e) Can not be determined 4) Assume a coin is equally weighted on both sides, what is the probability of Oor 1 heads when it is flipped 3 times: a) 1/8 b) 3/8 c).5 d) Can not be determined

Answer 1

(1) . (b) Bigger in size 2 than the sample size (2) Pl2 heads when a coin is flipped twice) Sample Space = {HH, HT, TH, TT} P ( 2 heads when a coin is flipped twice) = 1/2 Aus c=0.25 (3) when a coin is flipped 4 times Sample Space ={HHHH ,HHHT HHITH, HATTH THHATHI, HITHA HTTT THITH THAT THTHTHTT,T THAT LTTHY, TTTH ,TTTT no of heads = 5. e variable can take value o, 1,2,3,4 - Ans. (a) (4) For a coin to be flipped 3 times all = HHH ,HHT HTH HIT { LTHH, THAT, TTH TTTJ floor i heads) = $ + + 0 = = = yono Ans (6)

(5) when a couin is flipped 3 times on sample size = 80 . And cal 16) (e) None of the above .. (7) les sampling error decreases because the estimate of the poph mean will . improve while the standard deviation of the sample will tend to approximate the population standard deviation as sample seze increases (8) (C) Approximately normal (9) (9) Mean of sampling distribution of the mean is same as the mean population (10) (b) The sampling diskie bution of SD. (1 5E = 10 n=16 SE - SD . SD = n. 10 x4 - 40 Any (6) (12) u = 10; SD = lo, PL x >10) . n=25 Plz xo) = 0.5 Since poph is close to normal i. pl X-4 > 10-4 SD/50 SD/In Pl holdes loce) = P(Z >o) = 0.5 Ans (d)

(13) (as stay same (14) (a) (15) (c) it would Yes Unknown