survival_sex_rel: Survival rate based on Sex.
In unimi-dse/a2b3bab6: Analysis of survival of Titanic passengers.

This function analyses the relationship between Survival rate and sex of the passengers.

1	survival_sex_rel()

`df:`	The titanic train data set which we imported and converted to dataframe.
`sub_sex`	: subset which contains just the sex and survival rate of passenger
`fem_total`	:total females in the ship
`male_total`	:total males in the ship
`sur_sex`	:subset with only survived passengers
`female_survived`	: total female survived
`male_survived`	: total male survived
`mf_total:`	total analysis
`plot_sex`	: graphical representation of the relationship