Question

in a survey conducted by a reputable marketing agency, 245 of 1000 adults 19 years of age or older confessed to bringing and using their cell phone every trip to the bathroom (confessions included texting and answering phone calls) complete parts (a) through (f) below. (e) construct and interpret a 95% confidence interval for the population proportion of adults 19 years of age or older who bring their cell phone every trip to the bathroom. select the correct choice below and fill in any answer boxes within your choice (type integers or decimals rounded to three decimal places as needed. use ascending order.) a. there is a % probability the proportion of adults 19 years of age or older who bring their cell phone every trip to the bathroom is between and b. we are 95% confident the proportion of adults 19 years of age or older who bring their cell phone every trip to the bathroom is between 0.218 and 0.272 (f) what ensures that the results of this study are representative of all adults 19 years of age or older? select all that apply a. the high confidence level b. random sampling c. sampling from adults 19 years of age or older d. the large sample size

Explanation:

• Random sampling (B): Random sampling helps ensure that each individual in the population has an equal chance of being selected. This reduces bias and makes the sample more likely to be representative of the entire population (adults 19 years of age or older in this case). For example, if only a specific group (like those in a particular city or with a certain income level) was non - randomly selected, the results might not generalize.
• Sampling from adults 19 years of age or older (C): Since the population of interest is adults 19 years of age or older, sampling from this exact group is crucial. If the sample included younger individuals (not in the population of interest) or excluded some segments of the 19 + age group (like those in rural areas), the representativeness would be compromised.

The high confidence level (A) is about the certainty of capturing the true population proportion within the confidence interval, not directly about representativeness. The large sample size (D) can improve the precision of estimates (like the confidence interval width) but does not inherently ensure representativeness if the sample is biased (e.g., a large sample of only one type of 19 + adult, like only college students).

Answer:

B. Random sampling, C. Sampling from adults 19 years of age or older