Mobile device typing strategies. Refer to the Applied Ergonomics (March 2012) study of mobile device typing strategies, Exercise 10.13 (p. 611). Recall that typing style of mobile device users was categorized as (1) device held with both hands/both thumbs typing, (2) device held with right hand/right thumb typing, (3) device held with left hand/left thumb typing, (4) device held with both hands/right thumb typing, (5) device held with left hand/ right index finger typing, or (6) other. The researchers’ main objective was to determine if there are gender differences in typing strategies. Typing strategy and gender were observed for each in a sample of 859 college students observed typing on their mobile devices. The data are summarized in the accompanying table. Is this sufficient evidence to conclude that the proportions of mobile device users in the six texting style categories depend on whether a male or a female is texting? Use a = .10 to answer the question. Number of Females Both hands hold/both thumbs type 161 235 Right hand hold/right thumb type 118 193 Left hand hold/left thumb type 29 41 Both hands hold/right thumb type 10 29 Left hand hold/right index type 6 12 Other 11 14 Source: J. E. Gold et al., “Postures, Typing Strategies, and Gender Differences in Mobile Device Usage: An Observational Study,” Applied Ergonomics, Vol. 43, No. 2, March 2012 (Table 2).