Two students from aa class of 20 are chosen at random to escort a guest speaker to a presentation. The first student will introduce the speaker. The second will thank the speaker when she is done. In how many ways can the two students be chosen?

1. 1,960

2. 380

3. 240

4. 84

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed

The zoo collects $9.60 for every 24 tickets sold. how much will be collected for 400 tickets?

Aresearch study is done to find the average age of all u.s. factory workers. the researchers asked every factory worker in ohio what their birth year is. this research is an example of a census survey convenience sample simple random sample