The sex ratio of a district

A health worker has counted the girls and boys under six in five villages. You will write a function for the sex ratio, find it for every village, list the villages below $950$, and find the ratio of the whole district. The program then draws a bar chart.

The idea. Sex ratio $= \dfrac{1000 \times \text{girls}}{\text{boys}}$, rounded to a whole number. For the district, add all the girls and all the boys first.

Your tasks.

1. In sex_ratio, return the rounded ratio for girls and boys.
2. Fill the dictionary ratios with the ratio of every village.
3. Set low to the list of villages whose ratio is below 950, in alphabetical order.
4. Set district to the ratio of all the villages together.