Typographical and Spelling Errors Assignment | Assignment Help Services
Typographical and spelling errors can be either "nonword errors" or "word errors." A nonword error is not a real word, as when "the" is typed as "teh". A word error is a real word, but not the right word, as when "lose" is typed as "loose."
When undergraduates are asked to write a 250-word essay (without spell-checking), the number of nonword errors has the following distribution:Errors 0 1 2 3 4 Probability 0.1 0.3 0.3 0.2 0.1The number of word errors has this distribution:Errors 0 1 2 3Probability 0.4 0.3 0.2 0.1
Find the mean and standard deviation of the total number of errors (nonword errors plus word errors) in an essay if the error counts have the distributions given above and(a)the counts of nonword and word errors are independent.(b)students who make many nonword errors also tend to make many word errors, so that the correlation between the two error counts is 0.4.