A consumer product magazine recently ran a story concerning the increasing prices of digital cameras. The story stated that digital camera prices dipped a couple of years ago, but now are beginning to increase in price because of added features.
According to the story, the average price of all digital cameras a couple of years ago was 215.00. A random sample of cameras was recently taken and entered into a spreadsheet. It was desired to test to determine if that average price of all digital cameras is now more than 215.00. The information was entered into a spreadsheet and the following printout was obtained:
One-Sample T Test
Null Hypothesis: = 215
Alternative Hyp: > 215
95 Conf Interval
Variable Mean SE Lower Upper T DF P
Camera Price 245.23 15.620 212.740 277.720 1.94 21 0.0333
Cases Included 22
Use the p- value given above to determine which of the following conclusions is correct.
A) At = 0.10, there is insufficient evidence to indicate that the mean price of all digital cameras exceeds 215.00
B) At = 0.03, there is insufficient evidence to indicate that the mean price of all digital cameras exceeds 215.00
C) At = 0.01, there is sufficient evidence to indicate that the mean price of all digital cameras exceeds 215.00
D) At = 0.05, there is insufficient evidence to indicate that the mean price of all digital cameras exceeds 215.00
Q. 2About 40 of the general population donate time and energy to community projects. Suppose 15 people have been randomly selected from a community and each asked whether he or she donates time and energy to community projects.
Let x be the number who donate time and energy to community projects. Use a binomial probability table to find the probability that more than five of the 15 donate time and energy to community projects.
Q. 3A counselor obtains SAT averages for incoming freshmen each year for a period covering 14 years, with the objective of determining the relationship between the SAT score and the year the test was given.
The averages are then subjected to analysis for the purpose of drawing a conclusion regarding a trend. Determine whether the study is observational or designed.
A) observational B) designed
Q. 4The weight of corn chips dispensed into a 12-ounce bag by the dispensing machine has been identified as possessing a normal distribution with a mean of 12.5 ounces and a standard deviation of 0.2 ounce.
What proportion of the 12-ounce bags contain more than the advertised 12 ounces of chips?
A) .4938 B) .9938 C) .5062 D) .0062
Q. 5A bottling company produces bottles that hold 12 ounces of liquid. Periodically, the company gets complaints that their bottles are not holding enough liquid.
To test this claim, the bottling company randomly samples 64 bottles and finds the average amount of liquid held by the bottles is 11.9155 ounces with a standard deviation of 0.40 ounce. Suppose the p-value of this test is 0.0455. State the proper conclusion.
A) At = 0.05, reject the null hypothesis. B) At = 0.025, reject the null hypothesis.
C) At = 0.05, accept the null hypothesis. D) At = 0.10, fail to reject the null hypothesis.
Q. 6Suppose you selected a random sample of n = 29 measurements from a normal distribution. Compare the standard normal z value with the corresponding t value for a 95 confidence interval.
What will be an ideal response?
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