 Hello and welcome to the session. In this session we are going to discuss the following question and the question says that Stanley and Tim wants to know the main word length in our book. Stanley randomly selected 50 words from the book and Tim chose 50 words written on first page of the book. The number of letters in Stanley and Tim's words were 310 and 355 respectively. What conclusion can you draw for the main word length in the book for both the samples? Is there any variation in the estimate? First prediction is more reliable. Let's move on to the solution. In this question we are given that Stanley and Tim chose 50 words sample from the book where Stanley randomly selected 50 words from the book and Tim chose 50 words written on first page of the book. Also the number of letters in Stanley and Tim's words were 310 and 355 respectively. So here the population is all the words in the book. Now we need to draw a conclusion for the main word length in the book from both the samples and we know that mean in this context means average. Thus mean word length means average word length and this mean word length that is average word length would be equal to the total number of letters in your piece of writing divided by the total number of words here is a very simple example. Now in this sentence my pet rabbit likes piece total number of letters are 20 and total number of words are 5. So mean word length which is given by total number of letters divided by total number of words will be equal to 20 upon 5 that is 4. So here first Stanley mean word length will be given by total number of letters in his piece of writing that is 310 divided by total number of words which is 50 and this is equal to 6.2. Similarly first time mean word length in a sample is given by total number of letters in his piece of writing which is equal to 355 divided by total number of words that is 50 which is equal to 7.1. So first Stanley sample mean word length in the book approximately and first in sample mean word length is given by 7 approximately. Here we have rounded off the numbers because the number of letters cannot be infraction and here we have seen there is a variation in the length of words in both the samples. So we conclude there is a variation in the length of words in both the samples here Stanley had chosen a random sample and Tim had chosen the sample according to his convenience. So we can say Stanley's prediction is more reliable and we can say that the mean word length in the book is 6 approximately. This completes our session. Hope you enjoyed this session.