Why must private ownership of property be guaranteed before a free market economy will work?

Results of concept rating for new wine cooler rating of the appeal of the phrase as it relates to the new wine cooler total sample gender age male female 21 - 24 25 -34 35-49 extremely appealing (5) 151 68 83 48 63 40 somewhat appealing (4) 91 51 40 36 32 23 neither appealing nor not appealing (3) 36 21 15 9 16 11 somewhat unappealing (2) 13 7 6 4 6 3 not at all appealing (1) 9 3 6 4 3 2 quantity purchased per person in 4 weeks # of 6-packs purchased x # people who purchased 0 7 1 6 2 6 3 13 4 14 5 12 6 10 7 5 8 5 9 5 10 2 drinking temperature sample # temperature 1 52 2 46 3 50 4 42 5 52 6 50 7 39 8 44 9 49 10 39 11 47 12 46 13 43 14 52 15 49 16 47 17 49 18 52 19 50 20 47 21 49 22 38 23 57 24 49 25 49 26 57 27 45 28 58 29 54 30 44 what is the probability that a randomly selected 21 to 49 year old consumer is a males who gives the phrase a rating of 4?