According to a recent random survey of 3,728 US adults, 1,939 report using their cell phones to play online games. Construct and interpret a 95% confidence interval for the proportion of US adults who use their cell phones to play online games. State: confidence interval for the true proportion of US adults who use their cell phones to play online games. Plan: ; Random: Random survey; 10%: 3,728 is less than 10% of all US adults; Large Counts: 1,939 successes and 1,789 failures ≥ 10. Do: Conclude: We are 95% confident that the interval from includes the true proportion of all US adults to play online games.
✔ one-sample z-interval for ptwo-sample z-interval for pone-sample t-interval for mutwo-sample t-interval for mu
(0.464, 0.496)(0.499, 0.541)✔ (0.504, 0.536)(0.519, 0.520)
(0.464, 0.496)(0.499, 0.541)✔ (0.504, 0.536)(0.519, 0.520)
✔ who use their cell phoneswho used their cell phoneswho did use their cell phoneswho would have used their cell phones
Christian wants to estimate the proportion of seniors who plan to attend her school’s prom. She interviews an SRS of 65 of the 695 seniors in her school and finds that 42 plan to attend the prom. Construct and interpret a 90% confidence interval for the proportion of seniors who plan to attend the prom. State: confidence interval for the true proportion of seniors who plan to attend the prom. Plan: ; Random: SRS; 10%: 65 is less than 10% of all seniors; Large Counts: 42 successes and 23 failures ≥ 10. Do: Conclude: We are 90% confident that the interval from includes the true proportion of all seniors .
A nationwide random survey of 1,500 teens aged 13–17 found that approximately 65% have their own desktop or laptop computer. Construct and interpret a 99% confidence interval for the true proportion of teens who have their own desktop or laptop computer. State: confidence interval for the true proportion of teens who have their own desktop or laptop computer. Plan: ; Random: SRS; 10%: 1,500 is less than 10% of all teens; Large Counts: 975 successes and 525 failures ≥ 10. Do: Conclude: We are 99% confident that the interval from includes the true proportion of all teens .
An inspector at a popcorn factory selects a random sample of 75 bags of popcorn from the hundreds produced each hour and finds that 12 contain at least 10% unpopped kernels. Construct and interpret a 95% confidence interval for the true proportion of popcorn bags that contain at least 10% unpopped kernels. State: confidence interval for the true proportion of popcorn bags that contain at least 10% unpopped kernels. Plan: ; Random: SRS; 10%: is less than 10% of all bags of popcorn produced; Large Counts: 12 successes and 63 failures ≥ 10. Do: Conclude: We are 99% confident that the interval from includes the true proportion of all bags of popcorn at least 10% unpopped kernels.
Is it reasonable to conclude that more than half of US adults use their cell phones to play online games?
Is it reasonable to conclude that more than two-thirds of the seniors at Christian’s school plan to attend the prom?
Based on the interval, is it reasonable to conclude that a majority of teens aged 13–17 have their own desktop or laptop computer?
Based on the interval, is it reasonable to conclude that the machine needs to be recalibrated?
✔ one-sample z-interval for ptwo-sample z-interval for pone-sample t-interval for mutwo-sample t-interval for mu
✔ one-sample z-interval for ptwo-sample z-interval for pone-sample t-interval for mutwo-sample t-interval for mu
✔ one-sample z-interval for ptwo-sample z-interval for pone-sample t-interval for mutwo-sample t-interval for mu
(0.046, 0.075)(0.075, 0.112)(0.53, 0.762)✔ (0.549, 0.744)
(0.318, 0.382)(0.33, 0.37)✔ (0.618, 0.682)(0.649, 0.651)
(0.09, 0.23)✔ (0.077, 0.243)(0.051, 0.27)(0.037, 0.177)
(0.046, 0.075)(0.075, 0.112)(0.53, 0.762)✔ (0.549, 0.744)
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