Mathematics worksheets for class 12

I want a representative sample of likely voters. I use a telephone directory to randomly select 200 people. What is the most apparent bias?

I want to estimate the average number of hours ORH students spend playing video games. I sample all of my students. What kind of sampling bias is this?

I want to estimate the proportion of all adults in Chula Vista who graduated from high school. I select a random sample of addresses and go to those houses. When an adult answers the door, I ask if they had graduated from high school. If a child answers the door, I ask for an adult. If there is none there at the time, I return at another time to complete the survey. What is the most prominent bias?

I want to estimate the proportion of people in Chula Vista who own cats. I stand outside a local pet store and ask every 4th person whether they own a cat or not. What is the most prominent kind of bias evident?

Many websites like Amazon and Yelp include customer ratings and reviews of products, restaurants, hotels, and so on. What is the predominant bias evident in these ratings and reviews?

I want to estimate the study hours for students on campus. I survey students with at least one D or F on their report card. What kind of sampling bias is this?

“Some cell phone users have developed brain cancer. Should all cell phones come with a warning label explaining the danger of using cell phones?”

What kind of bias is evident in this survey question?