Nnenia wants to know how well she is doing in her statistics class. she has taken 10 quizzes in her statistics course, so far. her scores for the quizzes were 18, 10, 20, 15, 16, 18, 10, 12, 18, and 11. calculate the mode.

In the image, layer a is the topmost layer. layer c contains fossils from the precambrian era. layer b contains dinosaur fossils, and layer a contains fossils of mammals. which two statements are supported by this evidence? 1. mammals lived before the precambrian era. 2. dinosaurs and mammals existed in the precambrian era. 3. dinosaurs evolved after precambrian organisms. 4. precambrian organisms evolved after dinosaurs. 5. precambrian organisms were the first life-forms to become fossilized, according to this sample.