A random sample of 50 students in Holy Angel University shows that they spend an average of 3 hours per day on social media apps with a standard deviation of 0.5 hours. Assume a normal distribution. Construct a 90% and 97% confidence interval for the average number of hours spent on social media apps per day.

Q: A survey of 100 retailers revealed that the mean after-tax profit was $80,000. Assuming that the…

A: Given data,n=100σ=15,000x=80,000z-value at 95% confidence is Zc=1.96

Q: Use these data and a population standard deviation of 1.11 to construct a 98% confidence interval to…

A: The sample of 36 women's who had babies in the hospital during the past year is taken. The…

Q: From a random sample of 49 high school seniors, the sample mean and standard deviation of the math…

A:

Q: In a survey, 28 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: sample of 352 subscribers to Wired magazine shows the mean time spent using the Internet is 18.4…

A: Given data,n=352x=18.4s=6.8α=0.05df=n-1=351t-critical value is tc=1.967

Q: A sample of 40 cows is drawn to estimate the mean weight of a large herd of cattle. If the standard…

A:

Q: In a random sample of 60 computers, the mean repair cost was $150 with a standard deviation of $36.…

A: Solution is given below.

Q: A study conducted to examine the age of commercial jets in the United States sampled 36 planes and…

A: Given information- Sample size, n = 36 Sample mean, x-bar = 12.6 years Sample standard deviation, s…

Q: In a study investigating the average salaries of employees in a company, 36 employees of the company…

A: Solution: Given information: n=36 Sample size  x=2400  Sample mean s= 1200 Sample standard deviation…

Q: In a survey, 26 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: In a random sample of seven cell​ phones, the mean full retail price was ​$407.00 and the standard…

A: Solution: Let X bet the retail price of cell phone. From the given information, x-bar=$407, s=$196…

Q: In a random sample of twelve ​people, the mean driving distance to work was 21.5 miles and the…

A: Solution

Q: On the Standford-Binet test, the mean IQ is 100. A class of 21 kindergarten pupils were tested with…

A:

Q: In a random sample of 15 ​people, the mean driving distance to work was 18.5 miles and the standard…

A:

Q: The mean for the verbal component of the SAT is reported as 500, with a standard deviation of 100. A…

A: It is given that the sample mean is 498 and the population standard deviation is 100.

Q: In a random sample of 8 cell phones,the mean full retail price was $405.00 and the standard…

A:

Q: A sample of 352 subscribers to Wired magazine shows the mean time spent using the Internet is 18.4…

A: Given -  Sample size, n = 352 Mean time spent, x=18.4 hoursStandard deviation, σ=6.8 hours

Q: In a random sample of 12 people, the mean commute time to work was 30 minutes and the sample…

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Q: In a survey of a random sample of 49 college students, the sample mean time per week spent watching…

A: We have given that,  Sample mean (x̄) = 21, sample size (n)= 49, and standard deviation (s) = 8.2…

Q: In a random sample of ten ​people, the mean driving distance to work was 18.1 miles and the standard…

A:

Q: In a recent study of 42 eighth graders, the mean number of hours per week that they watched…

A: Mean = 19.6 Standard deviation = 5.8 Sample size n = 42

Q: A study of 64 bolts of carpet showed that their average length was 75 yards. The standard deviation…

A:

Q: In a random sample of ten people, the mean driving distance to work was 21.8 miles and the standard…

A: Given,sample size(n)=10mean(x)=21.8standard deviation(σ)=6.4α=1-0.99=0.01α2=0.005degrees of…

Q: 900 students were surveyed and had an average GPA of 2.7 with a standard deviation of 0.4. Calculate…

A: Given data,n=900Mean μ=2.7sd σ=0.4Z-value at 95% confidence is Zc=1.96 Calculate the margin of…

Q: Calculate a 90% confidence interval for the mean of the population, supposed normal, from which…

A: Given, Heights 63 63 66 67 68 69 70 70 71 71 Let X be height of  animal…

Q: In a sample of 90 large grade A eggs, the mean number of calories was 70 with a standard deviation…

A:

Q: During a natural gas shortage, a gas company randomly sampled residential gas meters in order to…

A: Solution: Let X be the gas consumption. From the given information, x-bar=250 cubic feet, S=50 cubic…

Q: Construct a 95% confidence interval for the population mean, μ. Assume the population has a normal…

A: Construction of the test statisticXi~Nμ , O2 , i =cn , independently⇒ x  ~N μ σ2n n-1S2σ2 ~ Xn-12…

Q: A statistician chooses 27 randomly selected dates, and when examining the occupancy records of a…

A: Givensample size(n)=27Variance(s2)=34.34conidence level=95%

Q: The secretary of administration in a master's program in business administration has observed that…

A: The confidence interval is an inference process which is used to estimate the population parameter.…

Q: In a random sample of seven cell​ phones, the mean full retail price was $477.50 and the standard…

A: Obtain the margin of error at the 99% confidence interval. The margin of error at the 99% confidence…

Q: In a random sample of eleven people, the mean driving distance to work was 25.7 miles and the…

A: Given that, n=no. of sample=11 x=mean=25.7 s=standard deviation=4.1 Confidence interval is 99%

Q: In a random sample of ten ​people, the mean driving distance to work was 23.2 miles and the standard…

A: Provided information is ; Sample size(n) =10  Mean(μ) = 23.2 Sample standard deviation(s) = 5.3…

Q: Construct a 95% confidence interval for the true average monthly salary earned by all employees of…

A:

Q: In a survey to estimate the mean time spent by office workers per day checking for and sending out…

A: From the provided information, Sample size (n) = 30 Sample mean (x̅) = 2 hours or 120 minutes…

Q: In a certain population, the number of hours per week that young people between 16 and 24 years of…

A: Given: Mean=12 Standard deviation=6

Q: In a random sample of eleven cell phones, the mean full retail price was $416.00 and the standard…

A:

Q: A study of a local high school tried to determine the mean number of text messages that each student…

A: Solution: Let X be the number of messages sent per day. From the given information, x-bar=198…

Q: In a random sample of 100 basketball players,the average vertical jump was 38 inches. If you somehow…

A: a) The margin of error is, Thus, the margin of error is 1.96 inches.

Q: n a crash test of 15 troopers, collision repair costs are found to have a distribution that is…

A: The summary of the statistics is, x¯=1800,s=950,n=15 The degree of freedom is, df =n -1     =15-1…

Q: .A sample of seven college wrestlers had an average weight of 267 pounds with a sample standard…

A: It is given that sample mean is 267 and the sample standard deviation is 10.

Q: In a survey, 23 people were asked how much they spent on their child's last birthday gift. The…

A: Givensample size(n)=23sample mean (x) = 31standard deviation (s) = 8α = 1-0.95=0.05α2=0.025degrees…

Q: In a random sample of twelve ​people, the mean driving distance to work was 18.8 miles and the…

A: From the given information we want to construct 90% confidence interval.

Q: The National Weather Service claimed that the average amount of snow in lowa is 11.52 inches. 10…

A:

Q: In a randoms sample of six people, the mean driving distance to work was 19.7 miles and the standard…

A: Given, sample mean (x̄) = 19.7 sample standard deviation (s) = 6.1 sample size (n) = 6 significance…

Q: In a survey, 21 people were asked how much they spent on their child's last birthday gift. The…

A: Margin of error is the error due to random sampling. The margin of error decreases with increase in…

Q: A college alumni Organization sent a survey to all recent graduates to ask their annual income. 20%…

A: Given, All recent graduates of a college were asked their annual income for a survey that was…

Q: In a random sample of ten cell phones, the mean full retail price was $554.00 and the standard…

A: Given that Sample size n = 10 Sample mean = 554.00 Sample SD = 167.00 The critical value of t at 95%…

Q: In a random sample of eleven ​people, the mean driving distance to work was 18.1 miles and the…

A: Given information Sample size (n) = 11 Sample mean x̅ = 18.1 miles Standard deviation (s) = 7.6…

Q: The director of vehicle maintenance for a large mass transportation authority wants to know the…

A: In this question, we have a sample of 100 tires and mean life of tire is 20,000 miles and standard…