Experts, here are 3 problems where I need help. Thanks a lot for the support!
1. Plz someone show how do this in a quick way (not just adding and finding the mean). Thanks!
70,75,80,85,90,105,105,130,130,130
The numbers above are the seconds it took each of 10 students to run 400 mts. If the standard deviation is 22.4, how many students are 1 standard deviation below the mean ?
OA after some discussion
2. A certain manufacturer of cakes, muffins and bread mixes has 100 buyers, of whom 50 purchase cake, 40 purchase muffin and 20 purchase muffin both cake and muffin mix. If a buyer is selected at random from the 100 buyers, what is the probability that the buyer selected will be one who purchases neither cake nor muffins?
OA after some discussion
3. A car averages 25 miles per galon (mpg) in the city and 40 mpg in the highway. Which of the following is the closest to the avergae mpg when car is driven 10 miles in the city and 50 miles in the highway?
a.28
b.30
c.33
d.36
e.38
OA after some discussion
1. Plz someone show how do this in a quick way (not just adding and finding the mean). Thanks!
70,75,80,85,90,105,105,130,130,130
The numbers above are the seconds it took each of 10 students to run 400 mts. If the standard deviation is 22.4, how many students are 1 standard deviation below the mean ?
OA after some discussion
2. A certain manufacturer of cakes, muffins and bread mixes has 100 buyers, of whom 50 purchase cake, 40 purchase muffin and 20 purchase muffin both cake and muffin mix. If a buyer is selected at random from the 100 buyers, what is the probability that the buyer selected will be one who purchases neither cake nor muffins?
OA after some discussion
3. A car averages 25 miles per galon (mpg) in the city and 40 mpg in the highway. Which of the following is the closest to the avergae mpg when car is driven 10 miles in the city and 50 miles in the highway?
a.28
b.30
c.33
d.36
e.38
OA after some discussion
