First, we need to calculate the total number of students in both seventh and eighth grade who play an instrument other than drums.
For seventh grade:
- Guitar: 12 students
- Bass: 3 students
- Keyboard: 14 students
Total seventh grade students who play an instrument other than drums: 12 + 3 + 14 = 29 students
For eighth grade:
- Guitar: 11 students
- Bass: 7 students
- Keyboard: 2 students
Total eighth grade students who play an instrument other than drums: 11 + 7 + 2 = 20 students
Total number of students who play an instrument other than drums: 29 (seventh grade) + 20 (eighth grade) = 49 students
Total number of students in both seventh and eighth grade: 12 (seventh grade guitar) + 3 (seventh grade bass) + 10 (seventh grade drums) + 14 (seventh grade keyboard) + 11 (eighth grade guitar) + 7 (eighth grade bass) + 13 (eighth grade drums) + 2 (eighth grade keyboard) = 72 students
Therefore, the probability that a student chosen at random will play an instrument other than drums is 49/72.
Jocelyn recorded the grade-level and instrument of everyone in the middle school School of Rock below.
Seventh Grade Students
Instrument # of Students
Guitar 12
Bass 3
Drums 10
Keyboard 14
Eighth Grade Students
Instrument # of Students
Guitar 11
Bass 7
Drums 13
Keyboard 2
Based on these results, express the probability that a student chosen at random will play an instrument other than drums as a fraction in simplest form.
7 answers
In a popular online role playing game, players can create detailed designs for their character's "costumes," or appearance. John sets up a website where players can buy and sell these costumes online. Information about the number of people who visited the website and the number of costumes purchased in a single day is listed below.
387 visitors purchased no costume.
71 visitors purchased exactly one costume.
17 visitors purchased more than one costume.
Based on these results, express the probability that the next person will purchase one or more costumes as a decimal to the nearest hundredth
387 visitors purchased no costume.
71 visitors purchased exactly one costume.
17 visitors purchased more than one costume.
Based on these results, express the probability that the next person will purchase one or more costumes as a decimal to the nearest hundredth
To calculate the probability that the next person will purchase one or more costumes, we need to consider the total number of visitors who made purchases.
Number of visitors who purchased exactly one costume = 71
Number of visitors who purchased more than one costume = 17
Total number of visitors who made purchases = 71 + 17 = 88
Now, we need to calculate the total number of visitors who visited the website without making a purchase.
Number of visitors who purchased no costume = 387
Total number of visitors who visited the website = Number of visitors who purchased no costume + Total number of visitors who made purchases
= 387 + 88
= 475
Therefore, the probability that the next person will purchase one or more costumes is calculated as the number of visitors who made a purchase divided by the total number of visitors who visited the website:
Probability = Total number of visitors who made purchases / Total number of visitors who visited the website
Probability = 88 / 475
Probability ≈ 0.1853
Rounded to the nearest hundredth, the probability that the next person will purchase one or more costumes is approximately 0.19.
Number of visitors who purchased exactly one costume = 71
Number of visitors who purchased more than one costume = 17
Total number of visitors who made purchases = 71 + 17 = 88
Now, we need to calculate the total number of visitors who visited the website without making a purchase.
Number of visitors who purchased no costume = 387
Total number of visitors who visited the website = Number of visitors who purchased no costume + Total number of visitors who made purchases
= 387 + 88
= 475
Therefore, the probability that the next person will purchase one or more costumes is calculated as the number of visitors who made a purchase divided by the total number of visitors who visited the website:
Probability = Total number of visitors who made purchases / Total number of visitors who visited the website
Probability = 88 / 475
Probability ≈ 0.1853
Rounded to the nearest hundredth, the probability that the next person will purchase one or more costumes is approximately 0.19.
Eva has a bag that contains pineapple chews, lemon chews, and watermelon chews. She performs an experiment. Eva randomly removes a chew from the bag, records the result, and returns the chew to the bag. Eva performs the experiment 19 times. The results are shown below:
A pineapple chew was selected 7 times.
A lemon chew was selected 6 times.
A watermelon chew was selected 6 times.
Based on these results, express the probability that the next chew Eva removes from the bag will be a flavor other than pineapple as a decimal to the nearest hundredth.
A pineapple chew was selected 7 times.
A lemon chew was selected 6 times.
A watermelon chew was selected 6 times.
Based on these results, express the probability that the next chew Eva removes from the bag will be a flavor other than pineapple as a decimal to the nearest hundredth.
To calculate the probability that the next chew Eva removes from the bag will be a flavor other than pineapple, we need to consider the total number of times a lemon chew or a watermelon chew was selected.
Number of times a lemon chew was selected = 6
Number of times a watermelon chew was selected = 6
Total number of times a lemon chew or a watermelon chew was selected = 6 (lemon) + 6 (watermelon) = 12
Since there were a total of 19 experiments conducted, the probability that the next chew Eva removes from the bag is a flavor other than pineapple is:
Probability = Total number of times a lemon chew or a watermelon chew was selected / Total number of experiments
Probability = 12 / 19
Probability ≈ 0.6316
Rounded to the nearest hundredth, the probability that the next chew Eva removes from the bag will be a flavor other than pineapple is approximately 0.63.
Number of times a lemon chew was selected = 6
Number of times a watermelon chew was selected = 6
Total number of times a lemon chew or a watermelon chew was selected = 6 (lemon) + 6 (watermelon) = 12
Since there were a total of 19 experiments conducted, the probability that the next chew Eva removes from the bag is a flavor other than pineapple is:
Probability = Total number of times a lemon chew or a watermelon chew was selected / Total number of experiments
Probability = 12 / 19
Probability ≈ 0.6316
Rounded to the nearest hundredth, the probability that the next chew Eva removes from the bag will be a flavor other than pineapple is approximately 0.63.
Andrew recorded the grade-level and instrument of everyone in the middle school School of Rock below.
Seventh Grade Students
Instrument # of Students
Guitar 7
Bass 10
Drums 9
Keyboard 12
Eighth Grade Students
Instrument # of Students
Guitar 15
Bass 9
Drums 2
Keyboard 8
Based on these results, express the probability that an eighth grader chosen at random will play an instrument other than bass as a decimal to the nearest hundredth.
Seventh Grade Students
Instrument # of Students
Guitar 7
Bass 10
Drums 9
Keyboard 12
Eighth Grade Students
Instrument # of Students
Guitar 15
Bass 9
Drums 2
Keyboard 8
Based on these results, express the probability that an eighth grader chosen at random will play an instrument other than bass as a decimal to the nearest hundredth.
To calculate the probability that an eighth grader chosen at random will play an instrument other than bass, we need to consider the total number of eighth-grade students who play an instrument other than bass.
In eighth grade:
- Guitar: 15 students
- Drums: 2 students
- Keyboard: 8 students
Total number of eighth-grade students who play an instrument other than bass: 15 (guitar) + 2 (drums) + 8 (keyboard) = 25 students
The total number of eighth-grade students is 15 (guitar) + 9 (bass) + 2 (drums) + 8 (keyboard) = 34 students
Therefore, the probability that an eighth grader chosen at random will play an instrument other than bass is:
Probability = Total number of eighth-grade students who play an instrument other than bass / Total number of eighth-grade students
Probability = 25 / 34
Probability ≈ 0.7353
Rounded to the nearest hundredth, the probability that an eighth grader chosen at random will play an instrument other than bass is approximately 0.74.
In eighth grade:
- Guitar: 15 students
- Drums: 2 students
- Keyboard: 8 students
Total number of eighth-grade students who play an instrument other than bass: 15 (guitar) + 2 (drums) + 8 (keyboard) = 25 students
The total number of eighth-grade students is 15 (guitar) + 9 (bass) + 2 (drums) + 8 (keyboard) = 34 students
Therefore, the probability that an eighth grader chosen at random will play an instrument other than bass is:
Probability = Total number of eighth-grade students who play an instrument other than bass / Total number of eighth-grade students
Probability = 25 / 34
Probability ≈ 0.7353
Rounded to the nearest hundredth, the probability that an eighth grader chosen at random will play an instrument other than bass is approximately 0.74.