7HEOC43-E Question Helpv at Regular gasoline averaged $2.68 per gallon in June 2018. Assume the standard deviation for gasoline prices is $0.15 per gallon. A random sample of 30 service stations was selected. Complete parts a through d. a. What is the probability that the sample mean will be less than $2.74? The probability that the sample mean will be less than $2.74 is 0.9857 . (Type an integer or decimal rounded to four decimal places as needed.) I). What is the probability that the sample mean will be more than $2.72'.7 The probability that the sample mean will be more than $2.72 is 0.0721 . (Type an integer or decimal rounded to four decimal places as needed.) 0. What is the probability that the sample mean will be between $2.71 and $2.78? The probability that the sample mean will be between $2.71 and $2.78 is (Type an integer or decimal rounded to four decimal places as needed.) 7..EOC44-E Question HelpV at Student loan debt is the only form of consumer debt that has grown since the peak of consumer debt in 2008. The average student loan of somebody younger than 30 is $20,950. Assume the standard deviation for debt is $5,000 per student, a. What is the probability that the sample mean will be less than $20,000 for a sample size of 40 students? b. Identify the symmetrical interval that includes 97% of the sample means if the true population mean is $20,950 per student. c. Answer the question in part a for a sample size of 80. Explain the differences in these two probabilities. a. The probability that the sample mean will be less than $20,000 is . (Type an integer or decimal rounded to four decimal places as needed.) @ 7.EOC.45-E Question Helpv O A health journal found that 56.4% of college students who lived in coed dormitories consumed alcohol weekly (compared with 26.5% who lived in singlesex dormitories). A random sample of 175 students who live in coed dormitories was selected. Complete parts a through d below. a. What is the probability that more than 50% of the students in the sample consume alcohol weekly? The probability is 0.9564 . (Round to four decimal places as needed.) b. What is the probability that less than 65% of the students in the sample consume alcohol weekly? The probability is . (Round to four decimal places as needed.) @ 7.EOC.47-E Question HeIpV a The ooncems about the impact of technology on our lives are growing. There have been recent research reports about the negative impact of digital technology usage on stress, work productivity, happiness, and overall well-being. In light of these concerns. a polling organization asked technology experts about their opinion on our digital life and found that 29% of the experts believe that in the future our lives will be more harmed than helped by their digital environment. In an effort to conrm these results, a local tech company decides to ask 210 randomly selected customers their opinions about their digital life. Answer parts a through :2 below. a. What is the probability that 35 or more people from this sample are concerned about the digital environment? The probability is 10000 ' (Round to four decimal places as needed.) b. What is the probability that 45 or more people from this sample are concerned about the digital environment? The probability is . (Round to four decimal places as needed.) 7HEOC50-E Question Help V 0 According to a government agency, the average workweek for an adult in June 2018 was 35.5 hours. Assume the population standard deviation for the number of hours worked per week is 5.0 hours. A random sample of 30 adults worked an average of 36.2 hours last week. a. Do the results from this sample support the claim by the government agency? b. Identify the symmetrical interval that includes 88% of the sample means if the true population mean is 35.5 hours per week. a. Do the results from this sample support the claim by the government agency? Consider a probability of less than 0.05 to be small. The probability that the sample mean will be greater than 36.2 hours is . The result : support the claim by the government agency that the mean is 35.5 hours because this probability is V 0.05. (Type an integer or decimal rounded to four decimal places as needed.) 7.EOC.53-E Question HeIpV O A road averages 2.555 vehicles per day with a standard deviation of 615 vehicles per day. Atrafc counter was used on this road on 38 days that were randomly selected' at What is the probability that the sample mean is less than 2,400 vehicles per day? b. What is the probability that the sample mean is more than 2,600 vehicles per day? c. What is the probability that the sample mean is between 2,500 and 2,700 vehicles per day? d. Suppose the sample mean was 2,800 vehicles per day Does this result support the stated population mean for this road? a. The probability that the sample mean will be less than 2,400 vehicles per day is (Type an integer or decimal rounded to four decimal places as needed) @ 7HEOC55-E Question Help V a In 2016 Americans owed $1.3 trillion in student loans The default rates of college student loans determine eligibility for colleges to receive federal student aid. According to the Department of Education, an average of 11.9% of Americans who had student loans defaulted on their loans. A random sample of 215 recent graduates was randomly selected, Complete parts a through d below. a. What is the probability that 10% or less of this sample has defaulted on their student loans? The probability is 0.1948 . (Round to four decimal places as needed.) b. What is the probability that 15% or more of this sample has defaulted on their student loans? The probability is . (Round to four decimal places as needed.) 7.EOC.58-E Question He.\" 4;} Obtaining a driver's license at the earliest eligible age has been a teenage ritual that appears to be fading. A study performed by a university's transportation research institute recently found that 28% of U5. teenagers between the ages of 17 and 19 did not possess a driver's license. A random sample of 150 17-to-19-yearold teenagers was selected. Complete parts a through d. a. What is the probability that 45 or fewer teenagers of this sample had not obtained a driver's license? The probability is 0.7073 . (Round to four decimal places as needed) b. What is the probability that 50 or more teenagers of this sample had not obtained a driver's license? The probability is . (Round to four decimal places as needed.) 7.EOC.59-E Question Help V at Suppose a person is employed at a college in which 62% of the student population is female. They are currently teaching statistics to 130 students this semester. They would like to select 40 students randomly from this group to participate in one of their research projects. Complete parts a through d below. a. What is the probability that 30 or more students in their sample will be female? The probability is . (Round to four decimal places as needed.)