PSQL query

PLease explain Thank you!!

Connect to the world database, write a query against the country table. Is it better to live in a country that starts with a vowel or consonant? Write a query that compares average life expectancy of contries with names that start with a vowel verses a consonant. Your query should ignore countries where life expectancy is NULL. Expected results: (Your column names should match) What does this mean? Countries that start with a vowel have an average life expectancy of 67.74 Countries that start with a consonant have an average life expectancy of 66.23