Answer:
Null Hypothesis,  : p
 : p  45%
 45%     
Alternate Hypothesis,  : p < 45%
 : p < 45% 
Step-by-step explanation:
We are given that the proportion of women in similar sales positions across the country in 2004 is less than 45%. 
The collected random sample of size 50 showed that only 18 were women.
<u><em>Let p = proportion of women in similar sales positions across the country in 2004</em></u>
So, Null Hypothesis,  : p
 : p  45%
 45%     
Alternate Hypothesis,  : p < 45%
 : p < 45% 
Here, <u><em>null hypothesis states that</em></u> the proportion of women in similar sales positions across the country in 2004 is more than or equal to 45%.
On the other hand, <u><em>alternate hypothesis states that</em></u> the proportion of women in similar sales positions across the country in 2004 is less than 45%.
The test statistics that would be used here is One-sample z proportion test statistics, i.e;
                         T.S.  =   ~ N(0,1)
  ~ N(0,1)
Hence, the above hypothesis is appropriate for the given situation.