Question

Typing errors in a text are either nonword errors (as when "the" is typed as "teh") or word errors that result in a real but incorrect word. Spell‑checking software will catch nonword errors but not word errors. Human proofreaders catch 70%70% of word errors.

You ask a fellow student to proofread an essay in which you have deliberately made 1010 word errors.

(a) If ?X is the number of word errors missed, what is the distribution of ?X ? Select an answer choice.

?X is approximately Normal with ?=3μ=3 and ?=1.45σ=1.45

?X is binomial with ?=10n=10 and ?=0.3p=0.3

?X is binomial with ?=10n=10 and ?=0.7p=0.7

?X is Normal with ?=7μ=7 and ?=1.45σ=1.45

If ?Y is the number of word errors caught, what is the distribution of ?Y ? Select an answer choice.

?Y is binomial with ?=10n=10 and ?=0.7p=0.7

?Y is binomial with ?=10n=10 and ?=0.3p=0.3

?Y is approximately Normal with ?=3μ=3 and ?=1.45σ=1.45

?Y is Normal with ?=7μ=7 and ?=1.45σ=1.45

(b) What is the mean number of errors caught? (Enter your answer as a whole number.)

mean of errors caught =

What is the mean number of errors missed? (Enter your answer as a whole number.)

mean of errors missed =

(c) What is the standard deviation of the number of errors caught? (Enter your answer rounded to four decimal places.)

standard deviation of the number of errors caught =

What is the standard deviation of the number of errors missed? (Enter your answer rounded to four decimal places.)

standard deviation of the number of errors missed =

Answer 1