According to a report on workforce diversity, about 60% of the employees in high-tech firms in Silicon Valley are whites and about 20% are Asians (moneycnn.com, November 9, 2011). Women, along with blacks and Hispanics, are highly underrepresented.

Just about 30% of all employees are women, with blacks and Hispanics, accounting for only about 15% of the workforce. Tara Jones is a recent college graduate, working for a large high-tech firm in Silicon Valley. She wants to determine if her firm faces the same diversity as in the report. She collects gender and ethnicity information on 50 employees in her firm. A portion of the data is shown in the accompanying table; the complete data set, labeled Silicon_Valley, can be found on the text website.

GenderEthnicity

Female........White

Male........White

: .......... :

Male........Nonwhite

a. At the 5% level of significance, determine if the proportion of women in Tara’s firm is different from 30%.

b. At the 5% level of significance, determine if the proportion of whites in Tara’s firm is more than 50%.