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A study was conducted in order to estimate μ, the mean number of weekly hours that U.S. adults use computers at home. Suppose a random sample of 81 U.S. adults gives a mean weekly computer usage time of 8.5 hours and that from prior studies, the population standard deviation is assumed to be σ = 3.6 hours. A similar study conducted a year earlier estimated that μ, the mean number of weekly hours that U.S. adults use computers at home, was 8 hours. We would like to test (at the significance level of 5%) whether the current study provides significant evidence that this mean has changed since the previous year. Using a 95% confidence interval of (7.7, 9.3), our conclusion is that:

A statistics student would like to investigate if the mean number of Facebook friends among all CCC college students is higher than 130.From her survey data, the student calculates that the mean number of Facebook friends for her sample is 138.7 with a standard deviation of 79.3. She analyzed her data using a t-test and obtained a P-value of 0.23.What conclusion can she draw from her data?

Complete on paper, detail your process Suppose it’s known that 14% of high schoolers drive themselves to school every day. a) If we consider a random sample of 120 high schoolers, would 23 of those students driving themselves be significantly different?  Use

Complete on paper, detail your process In 2012 Kelly Blue Book claimed that the average length of car ownership had increased to 57 months. Gwen questions whether this is really true.  She studies 1000 cars in her city and finds that the average length of ownership is 58 months with standard deviation 10. Is that significantly different (with

Complete on paper, detail your process In 2012 Kelly Blue Book claimed that the average length of car ownership had increased to 57 months. Gwen questions whether this is really true.  She studies 1000 cars in her city and finds that the average length of ownership is 58 months with standard deviation 10. Is that significantly different (with

We have conducted a one sided hypothesis test with a 1% significance level ( = 0.01). We would like to also construct a confidence interval with an equivalent level so that we can compare our results. What should the confidence level of this interval be?

We have conducted a one sided hypothesis test with a 1% significance level ( = 0.01). We would like to also construct a confidence interval with an equivalent level so that we can compare our results. What should the confidence level of this interval be?

Complete on paper, detail your process Suppose it’s known that 14% of high schoolers drive themselves to school every day. a) If we consider a random sample of 120 high schoolers, would 23 of those students driving themselves be significantly different?  Use

Did you attempt this problem on your paper?   Nial is driving home from work when they notice their GPS tracking average speed.  With nothing better to do, he assumes that the speed follows a roughly normal distribution with a mean of the stated average speed (32 miles per hour) and a standard deviation of about 2 mph. a) On a given trip, what is the probability that Nial’s average speed is above 35mph? b) If the posted speed limit along his route is 30mph, what is the probability that Nial’s trip average is slower than that? c) What is the probability that Nial’s average speed will fall between 29 and 35mph on a given day? c) What average speed would be unusually fast?

Did you attempt this problem on your paper?   Role  // Type of vehicle Midrange Cars Sports Cars SUV Truck Faculty 29 7 24 11 Student 126 41 183 98           Given the information in the table, answer the following. a) How many faculty were interviewed? b) How many of those interviewed drove Sports Cars to school? c) What is the probability that if a random student were selected, they would tell you they drove a truck? d) What is the probability that a random faculty member is selected, they would tell you they drove a truck? e) Compare the last two answers and explain any conclusions you can draw.