According to a 2018 report by CNBC on workforce diversity, about 60% of the employees in hightech firms in Silicon Valley are white and about 20% are Asian. Women, along with African Americans and Latinxs, are highly underrepresented. Just about 30% of all employees are women, with African Americans and Latinx 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 sex and ethnicity information on 50 employees in her firm. A portion of the data is shown in the accompanying table.

Sex                                                              Ethnicity 

Woman........................................................ White 

Man...............................................................White 

⋮ ......................................................................... ⋮ 

Man......................................................... Nonwhite  

a. At the 5% level of significance, determine if the proportion of women in Tara’s firm is different from 0.30. 

b. At the 5% level of significance, determine if the proportion of whites in Tara’s firm is more than 0.50.