A survey stopped men and women at random to ask them where they purchased groceries, at a local grocery store or online.
Grocery Options
Store Online Total
Women 37 12 49
Men 40 11 51
Total 77 23 100
What percent of the men surveyed shop online? Round your answer to the nearest whole number percent.
The percentage of men surveyed who shop online is:
(11/51) x 100% = 21.57%
Rounding to the nearest whole number percent, we get:
22%
A survey asked a random sample students if they estimated they spent more or less than an hour a day on social media.
Social Media
More Less
7th grade 16 26
8th grade 13 12
What percent of the 8th graders estimated they spend more than an hour a day on social media? Round your answer to the nearest tenth of a percent.
The total number of students in 8th grade who were surveyed is:
13 + 12 = 25
The percentage of 8th graders surveyed who estimated they spend more than an hour a day on social media is:
(13/25) x 100% = 52%
Rounding to the nearest tenth of a percent, we get:
52.0%
A random sample of students were surveyed as to how much non-school screen time they had each week (for purposes of the survey, screen time was defined as: time spent online, on social media, watching TV, or playing video games) and if their grade average was above or below 80.
Screen Time
above below Total
less than 4 hours 9 9 18
4-8 hours 14 11 25
8-12 hours 12 11 23
more than 12 hours 13 14 27
Total 48 45 93
How many students who spend less than 4 hours a week on screens reported a grade average above 80?
The number of students who spend less than 4 hours a week on screens and reported a grade average above 80 is:
9
Naomi recorded the grade level and instrument of everyone in the middle school School of Rock below.
School of Rock
Guitar Bass Drums Keyboard Total
6th grade 13 12 17 19 61
7th Grade 20 16 13 20 69
8th Grade 11 16 16 15 58
Total 44 44 46 54 188
How many students in the School of Rock play bass?
The number of students in the School of Rock who play bass is:
44
In a class of students, the following data table summarizes the gender of the students and whether they have an A in the class. What is the probability that a student who has an A is a female?
Female Male
Has an A 2 3
Does not have an A 11 12
There are a total of 2 + 3 + 11 + 12 = 28 students in the class.
Out of the students who have an A, 2 of them are female.
Therefore, the conditional probability of a student who has an A being female is:
2 / (2 + 3) = 2/5 = 0.4
So the probability that a student who has an A is a female is 0.4, or 40%.
In a class of students, the following data table summarizes the gender of the students and whether they have an A in the class. What is the probability that a female student does not have an A?
Female Male
Has an A 2 3
Does not have an A 12 11