Hi kipsombilwa,

thanks for your help with my statistic homework Unfortunately I tried the first lot of question and two of your answers out of three were wrong. I failed the first section of my perdisco test. I just thought I let you know. Please see the screenshot attached. Hav

Introductory Statistics Third Edition Perdisco Assessment [feedback page] This is a feedback page. You have NOT yet finished your assignment. Please read the following paragraph carefully. When you are ready, you must complete this assignment by clicking finish. You will then see your final score. 1 of 2 ID: MST.FET.P.ANOP.01.0030A [2 marks] marks] Two friends, Helen and Harriet, have a coin. Helen spent all day flipping the coin thousands of times, and observed that it turned up heads 60% of the time. So Helen assigns a probability of 0.6 to the event that a head turns up. Harriet, who is unaware of Helen's flipping experiment, reasons that the coin has two sides, each side being equally likely to show up. So Harriet assigns a probability of 0.5 to the event that a head shows up. a) A relative frequency approach to probability is demonstrated by: Helen Harriet both Helen and Harriet b) A weakness with the probability assigned by Helen is that: it must be wrong, the probability must be 1/6 it is an estimate probability has nothing to do with how often an event is seen to occur Feedback [1 out of 2] a) This is not correct. A relative frequency approach to probability is demonstrated by Helen. b) You are correct. Discussion There are two main definitions of probability - the relative frequency definition and the a priori classical definition: relative frequency definition - the probability of an event in a random process is estimated, through repeated trials of an experiment, to be the number of times that the event is observed divided by the total number of trials. a priori classical definition - the probability of an event is defined by considering all the possible outcomes of a random process (the sample space) and also considering how many of these outcomes are in your event. Then the probability of an event, A, is defined to be: number of outcomes in A P(A) = number of outcomes in sample space So with the relative frequency approach, the probability of an event in a random process is estimated, through repeated trials of the process, to be the number of times that the event is observed divided by the total number of trials. (And usually we assume that a large number of trials are used.) a) It is Helen who flips the coin many times and assigns a probability to the event that a head turns up based upon the result of those many trials. Therefore, a relative frequency approach to probability is demonstrated by Helen. b) A particular limitation of the relative frequency approach is that the probability is estimated from experiment and is therefore an approximation. Ideally, if you could run infinitely many trials, you could reduce any error to zero, but obviously you cannot and there will always be some error in your estimation. Running separate trials for determining the probability of the same event will usually give similar but strictly not equal values for the probability of the event. Thus since it is a relative frequency probability, a weakness with the probability assigned by Helen is that it is an estimate. 2 of 2 ID: MST.FET.P.ANOP.02.0030A [1 mark] mark] Four students attempt to describe the likelihood of an event. They all assign a probability to this event. The table to the right shows each student together with the probability that they have assigned. Student Probability Karen 0 Based only on this information, the student that believes that the event is certain is: Linda 0.5 Miranda 1 Natalie 2 Natalie Miranda Linda Karen Feedback [0 out of 1] This is not correct. Based only on this information, the student that believes that the event is certain is Miranda. Discussion Two of the most basic rules of probability are: 1. The probability of any event is always between 0 and 1. 2. If the probability of an event is 0, this means the event is impossible and never occurs. If the probability of an event is 1, this means the event is certain and will always occur. The second of these rules is the most relevant to this question. It is Miranda who assigns a probability of 1 to the event in question. According to the second rule above, this means that she believes that the event is certain and will always occur. Perdisco / latin /, v., to learn thoroughly 2010 Perdisco Terms Of Use | Privacy Policy | Sunday, April 17, 2016, 08:34 http://www.perdisco.com.au