Calculating Confidence Interval for p

Latoya wants to estimate p = the proportion of all students at her large boarding high school that like the cafeteria's food. She interviews an SRS of 50 of the students living in the dormitory and finds that 14 think the cafeteria's food is good. Calculate a 90% confidence interval for the proportion of students at Latoya's school who like the cafeteria's food.

• 0.176 to 0.384

• 0.28 to 0.104

• 0.28 - 0.104

• 0.28 + 0.104

An online retailer wants to estimate p = the proportion of all orders in a given week that are from new customers. He takes an SRS of 40 orders and finds that 12 of them are from new customers. Calculate a 99% confidence interval for the proportion of the week's orders that are from new customers.

• 0.113 to 0.487

• 0.30 to 0.187

• 0.30 + 0.187

• 0.30 - 0.187

In her first-grade social studies class, Jordan learned that 70% of Earth's surface is covered in water. She wondered if this is true and asked her dad for help. To investigate, he tossed an inflatable globe to her 50 times., being careful to spin the globe each time. When she caught it, he recorded where her right index finger was pointing. In 50 tosses, her finger was pointing to water 33 times. Construct a 95% confidence interval for the proportion of Earth's surface that is covered in water. Assume that the conditions are met.

• 0.66 to 0.131

• 0.529 to 0.791

• 0.66 + 0.131

• 0.66 - 0.791

After hearing that the majority of couples tilt to the right when kissing, Stephanie wanted to know the proportion of students who lean to the right when hugging a friend. She observed 51 different hugs and recorded 23 where the huggers leaned to the right. Construct a 95% confidence interval for the proportion of the students at Stephanie's school that lean to the right when hugging a friend. Assume the conditions are met.

• 0.314 to 0.451

• 0.314 to 0.588

• 0.451 to 0.137

• 0.451 + 0.137