Statistics and Probability Answers

Mention explain mathematically and illustrate/show/draw/copy-and-paste a cultural artefact where rotation is used to develop the pattern or artistic effect.

ten dry cells were taken from store and voltage tests gave the following results: 1.52,1.53,1.49,1,48,1.47,1.49,1.51,1.50,1.47,1.48 volts. the mean voltage of the cells when stored was 1.51v. assuming the population standard deviation to remain unchanged at 0.02v,

With numbers we know that x < y if we have that x lies to the left of y on the number line

• Find another way to see whether x < y that uses subtraction and natural numbers ?

Form a group of eight students in your class or section. Determine the general weighted average of the members of the group. List them

1.list all the possible samples of size 2 and their corresponding means

2.construct the sampling distribution of the sample means

3.calculate the mean of the sampling distribution of the sample means

The following are the heights of four students in centimeters. Suppose samples of size 2 are taken from this population of four students.

Question: How many samples are possible? List and compute the mean of each sample.

From a survey, 48 out of 50 females voted "no" and 30 out of 50 male voted also for "no". Construct a point estimate for the difference of the population

A bag contains 14 identical balls of which 5 are red, 3 black and 6 white balls. Four balls are drawn at random from the bag. Find the probability that (i) one is white

1. In March 2014, the Gallup Organization found in a survey that 42% of U.S. adults think global warming is greatly exaggerated. The number of adults polled was 1,048.
2. Can we say that less than half (significantly more than 50% at an alpha level of .05, using a two-tailed alpha test – this means .025 in each tail) of U.S. adults believe global warming is greatly exaggerated?  Here the p for your H0 (null hypothesis) is p=.50. is the p you should use in your standard error (SE) formula.
3. This same survey finds that 68% Republicans believe global warming is greatly exaggerated compared to 18% Democrats. The survey is that same as above - administered to 1,048 adults, 400 of whom were Republicans and 450 of whom were Democrats (the rest were independents)
4. Using information from question #1, with hypothesis testing can we say that fewer Democrats think global warming is exaggerated than Republicans? Why or why not? Use an alpha level of .01 this time with a two-tailed test (99% confidence).

1. From a random sample of 8^th graders, we find that the mean math score is 51.3. The standard deviation is 9.9. The sample size is 6,127. Construct a confidence interval for 95%. With 95% confidence, what is the interval that encompasses the true population mean? Answer this in one sentence.

Using the same example as above, can we say with 95% confidence (using a two- tailed test) that the mean math score in the population is above 50? Test this hypothesis. Compare the hypothesis test with the results from your confidence interval. Are they consistent?

From this same survey, we find the mean math score is 50.8 for girls and 51.8 for boys. The standard deviation for girls is 9.5 and the standard deviation for boys is 10.3. There are 3,129 girls in the sample and 2,998 boys. Test the hypothesis that the mean for boys and the mean for girls are different at the .05 alpha level (95% confidence) using a two-tailed test. Use df=6,028. 

Your mother said you can buy three boxes of Cracker Jacks. What is the probability that you will find one tattoo out of those three boxes? The probability of finding a tattoo in a single box of Cracker Jacks is .20.