Lathrop, California. Lathrop is a city located in San Joaquin County, California, United States. At the 2010 census Lathropâs population was 18,023. The city is located in Northern California at the intersection of Interstate 5 and SR 120. Contents.
The lowest composite ACT score possible is 1, while the highest ACT score possible is 36. Other factors will help you determine what a good ACT composite score is for you, and weâll look at those in a minute.
1 Earn an ACT English score of at least 24 or SAT Verbal score of at least 550.  Rank in the top 25 percent of your class and earn an ACT English score of at least 23 or SAT Verbal score of at least 540.