Answer:
Simple random sampling
Observational study
Step-by-step explanation:
Since in the given situation it is mentioned that department wants to test the computer virus and have to run the virus on the random selected computers so here the simple random sampling would be done and based on the simple random sampling the observational study would be done
Therefore the above represent the answer
22 since it occurs the most.
First we need to convert yard to miles
3520yards÷1760yards/mile=2 miles
From there we know:
Alex walked 1 mile for 15 mins and Sally walked 2mile in 24 mins
We need to convert these mileages to miles per hour
1mile/15mins*60mins/hour=4miles /hour
2mile/24mins*60mins/hour=5miles per hour
Alex walks at 4 miles per hour and Sally at 5 miles per hour
Sally walks 1 mile per hour faster than Alex
