Question

4. A department store has daily mean sales of $ 28,372.72. The standard deviation of sales is $2000. On Tuesday, the store sold $34,885.21 worth of goods. Find Tuesday's z score. 5. The following table contains data from a study of two airlines which fly to Small Town, USA. If one flight is is selected, find the probability that the flight was on time or Upstate Airlines Plon time or Upstate Airlines) = ? Number of ſights Number of flights which were on time which were late Podunk Airlines 33 Upstate Airlines 43 5 6

Please show all work step by step! and round answers to 4 decimal places.

Answer 1

4) z-score = (x - mean)/SD

= (34885.21 - 28372.72)/2000

= 3.2562

5) P(on time or Upstate Airlines) = P(on time) + P(Upstate Airlines) - P(on time and Upstate Airlines)

= 76/87 + 48/87 - 43/87

= (76 + 48 - 43)/87

= 81/87 = 0.9310