A wine producer believes that a new advertisement will increase product sales in LCBO by an average of 50 cases in a week. For a random sample of 20 LCBO stores, it was found that the average sales increase was 41.3 cases, and the sample standard deviation was 12.2 cases. Test the null hypothesis that the population mean sales increase is at least 50 cases, stating any assumptions you can make. Use 5% as a significant level. (You NEED to use BOTH the Critical-value approach and p-value approach to get a full mark). a) None of the answers are correct Ob) Do not reject the null hypothesis

In March 2016, it was reported that key American brands had increased their daily Instagram posts from 0.89 per day at the end of 2014 to 1.04 posts per day by the end of 2015.  With consistent samples sizes of 10,000 each for December 2014 and December 2015, the sample standard deviation for 2014 was 6.5 posts per day and 5 posts per day in 2015.  Julian Gottke, writing for Quintly, seemed to indicate that the increase from 0.89 posts per day to 1.04 posts per day was significant. To test whether this increase was statistically significant, a one-tail hypothesis test of the means of two independent populations using the t statistic was ordered.   How would I set up my null and alternative hypothesis and determine the levels of significance and compute the test statistic?

in a test of a lifelong brand of tires , a survey revealed that the mean life was 35,000 mikes and the standard deviation was 7083 mikes.  if the shape of the population distribution is known to be normal, approximately what percentage of the tires lasts less than 20834 miles ?

An article in the San Jose Mercury News stated that students in the California state universitysystem take 4.25 years, on average, to finish their undergraduate degrees. Suppose you believe that the mean time is longer. You conduct a survey of 64 students and obtain a sample mean of 4.5 with a sample standard deviation of 1.5. Do the data support your claim at the 1% level?

You are interested in testing whether the average age of household heads is higher in the suburbs than in inner city neighbourhoods. A survey is conducted, and the following results are obtained. In the suburbs, the household heads of the 45 households surveyed had a mean age of 44 with a standard deviation of 15. In the inner city, the mean age of the 40 household heads surveyed was 38 with a standard deviation of 13. Assuming that the populations from which these samples were drawn have equal variances, can you conclude that the difference between the two means is significant at the 95% level of confidence? (a) Write in words and symbols the null and research hypotheses. (b) Assuming the variances of the populations are equal, calculate the value of the Pooled Variance Estimate (PVE). (c) Calculate the value of the standard error for the difference between the two means.

An analyst found that the average amount of money in bank accounts at his/her bank is $2,000 with a standard deviation of $150.  What would be the variance?

Airline companies are interested in the consistency of the number of babies on each flight, so that they have adequate safety equipment. They are also interested in the variation of the number of Babies. Suppose that an airline executive believes the standard deviation in the number of babies is 6 at the most. The airline conducts a survey. The results of the 23 flights surveyed give a samle mean of 8 with a sample standard deviation of 9. Test the executive's belief to see if it is accurate, or if it is actually greater at the a = 0.05 level. Ho:o = H:o Select an answer df = P-value = The p-value is... greater than a less than (or equal to) a This test statistic leads to a decision to... reject the null fail to reject the null accept the alternative accept the null As such, the final conclusion is that there Select an answer v sufficient evidence to conclude the standard deviation of the number of babies on airplanes is Select an answer than (?

The Department of Agriculture wants to determine whether the mean yield per acre for a particular variety of soybeans is different this year compared to the historical avg yield of 520 bushels per acre. Thus, the null and alternative hypotheses are  Ho: mu = 520 Ha: mu is not = to 520 You set out to conduct a hypothesis test at the 95% level. Mean yields are distributed Normally. You take a sample of 36 different acres. From this sample, you calculate a mean yield of 573 and a std deviation of 24.  Do you reject or not-reject the null hypothesis? Group of answer choices Do not reject the null hypothesis. Reject the null hypothesis.

In the class of 2019, more than 1.6 million students took the SAT. The distribution of scores on the math section (out of 800) is approximately normal with a mean of 528 and standard deviation of 117.  What proportion of students earned scores between 500 and 600 on the SAT math test?

A hiring company claims that the variance of the annual salaries for managers is greater in Florida than Georgia. You select a sample of 28 managers in Florida and find the standard deviation to be $11,000. You select a sample of 24 managers in Georgia and find the standard deviation to be $9,200. At α=0.05, can you support the hiring company's claim?