AP Statistics Discrete Random Distributions Period Date Typographical and spelling errors can be either "non-word errors" or "word errors." A non-word error is not a real word, as when "the" is typed "teh." A word error is a real word, but not the right word, as when "lose" is typed as "loose." Students were asked to write a 50 word essay with spell check turned off. The number of errors was recorded. world gaimuseA .avoda aroundrueb owns and) andmon sw saoqque The number of non-word errors X has the following probability distribution: Non-word errors X: O 1 2 3 4 Probability (p): 0.1 0.2 0.3 0.3 0.1 28W 11 1. Find the expected value (mean) of this distribution. Use the equation to show your work! Y+ X - T snarlw al -(T)2 = 91052 2. Find the standard deviation for this distribution. Use the equation to show your work! Seexeleim To # Isjol sift 101 snooz ed To1 nousiveb busbrisia ardi at tedW d The number of word errors Y has the following probability distribution: bomnew word errors Y: dmo 2 3 Puts a amoldong songl .8 Probability (p): on b10).4 bus 0.3 w 0.2 59 0. 1ongallib era bril or hi blow ladW 3. Find the expected value (mean) of this distribution. Use the equation to show your work! sensistlib eris not ed nousiveb Isbasie ords bloow ww d 4. Find the standard deviation for this distribution. Use the equation to show your work!5. Suppose we combine the two distributions above. Assuming they are independent, what would the combined mean be for X + Y? el sowe know-mon A Setone blow to "etome brow-nou" folio ed ase monis guilloge bre Insidergogy T ofT Ho bemul sloedo llage threw vsees blow De s stitw of bowles slow amnobule scool" as bogg ar "ogol" 6. Suppose we combine the two distributions above. Assuming they are independent, what would the combined variance be for X + Y? dedong gniwollot grij and X cloris blow-non to andmed sT A & S 0 :X elms brow-now 7. It was decided that students would be assessed a point value for each mistake they made. The higher the total, the worse the student does. The following equation was developed to assess the points. Score = 5(T) -15 where T = X +Y a. What is the expected value for the score for the total # of mistakes? bhow wov worle of nobisups grit 92U .noundivetheirh tol nousiveb bisbasie ard ball .S b. What is the standard deviation for the score for the total # of mistakes? norudinaib wilidsdong gniwollol orfiend Y aron9 how to 19dmun onT 8. Ignore problems 5 through 7 and assume that we did not combine the scores. Suppose we wanted to find the difference between the non-word error and the word errors, X - Y. dede19 a. What would the expected value be for the difference? blow moy words of nousups or 93U .nobudreib aim to (noem) plev bemagee ard ball .C b. What would the standard deviation be for the difference Show woy worle of nobsups sil saU .woundruzib airi tol nonsiveb binbusje esh built A