Statistics Probabilities

Statistics Probabilities Questions with Work

1.      Suppose we want to determine the (binomial) probability (p) of getting 5 heads in 15 flips of a 2 sided coin. 

Using the Binomial table in the appendix

of the text, what values of n, x, and p would we use to look up this probability, and what would be the probability?

For starters: 

I went here and found this which I am sharing because I feel others may want to use this in the future:

http://stattrek.com/online-calculator/binomial.aspx

However, I went to SU tutors and received help. I screen shot everything this time. I am now going to protect myself from tutors that make mistakes and lie about it. This time, I had a tutor that in fact made a mistake and corrected it, and even explained everything thoroughly. 

Here is what I learned from Asmita:

n=15 x=5 p=0.5 (1/2) and for the final answer: .092

2.      Learning is a lifetime activity. For some, it means learning from everyday experiences; for others, it means taking classes in a more

traditional atmosphere. The percentage of people participating in

organized learning situations during 2002 for each age group is

reported here by NIACE.

Is this a probability distribution, why or why not? No, I do not ‘think’ this graph that I cannot include in this question is a probability distribution. Why? Because this is not a flip of a coin experiment. However, my first question, ‘is’ a probability experiment, I’m just sayin…

Practice Quiz with Answers Statistics College Edition

Practice Quiz Statistics College Edition

MULTIPLE CHOICE.  Choose the one alternative that best completes the statement or answers the question.

Determine whether the given value is a statistic or a parameter.

1.) After inspecting all of 55,000kg of meat stored at the Wurst Sausage Company, it was found that 45,000 kg of the meat was spoiled.

_____B_

A) Statistic

B) Parameter

2.) Determine whether the given value is from a discrete or continuous data set.

The temperature of a cup of coffee is 67.3°F.

___A___

 

A) Continuous

B) Discrete

3.) Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate.

Survey responses of "good, better, best".

___D___

A) Interval

B) Ordinal

C) Ratio

D) Nominal

4.) Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience.

A market researcher selects 500 people from each of 10 cities.

_A_____

A) Cluster

B) Random

C) Stratified

D) Systematic

E) Convenience

5.)Provide an appropriate response.

  

An education expert is researching teaching methods and wishes to interview teachers from a particular school district. She randomly selects ten schools from the district and interviews all of the teachers at the selected schools. Does this sampling plan result in a random sample? Simple random sample? Explain.

 

____B__

No; yes. The sample is not random because teachers in small schools are more likely to be selected than teachers in larger schools. It is a simple random sample because all samples have the same chance of being selected.

B)

Yes; yes. The sample is random because all teachers have the same chance of being selected. It is a simple random sample because all samples have the same chance of being selected.

 

C)

No; no. The sample is not random because teachers in small schools are more likely to be selected than teachers in larger schools. It is not a simple random sample because some samples are not possible, such as a sample that includes teachers from schools that were not selected.

D)

Yes; no. The sample is random because all teachers have the same chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample that includes teachers from schools that were not selected.

6.) ESSAY.  Write your answer in the space provided or on a separate sheet of paper. You will need to show your work on these problems!

Last year nine employees of an electronics company retired.  Their ages at retirement were:

B

56   65   62

53   68   58

67   52   56

a)  Find the Mean retirement age.  _59.67____

b)  Find the Median.     _58____

c)  Find the Midrange.  __60___

  

7.)Find the variance for the given data. Round your answer to two decimal places.

           Be sure to show ALL work and calculations!

a)    18   16   12   2   11

 

___B_

1.) 38.10

2.) 30.62

3.) 38.20

4.) 6.18

b)    Find the standard deviation for these data.   _ Variance = 38.20; SD = 6.18 __ .

work:

	values		dev. from mean	dev. Squared
	18		6.2	38.44
	16		4.2	17.64
	12		0.2	0.04
	2		-9.8	96.04
	11		-0.8	0.64
Mean =	11.8		0	38.20	Variance
				6.18	SD

8.)Determine which score corresponds to the higher relative position.

Which is better: a score of 82 on a test with a mean of 70 and a standard deviation of 8, or a score of 82 on a test with a mean of 75 and a standard deviation of 4?  Show all work!

_(82-75)/4=1.75=z

Work:

(82 – 70)/8 = 1.5 =z(82 – 75)/4 =1.75 = z     The larger z score is better.

9.)Use the given sample data to find Q3.  Always show your calculations!

                49   52   52   52   74   67   55   55

Work:

49   52 52  52  55  55  67  74   Answer is (55 + 67)/2 = 61, which reflects the Median of the upper half of the scores.

__c_____

A) 55.0

B) 6.0

C)61.0

D)67.0

10. ) The test scores of 40 students are listed below. Find P56.  Please show all work!                    10)_23rd_____

                30   35   43   44   47   48   54   55   56   57

                59   62   63   65   66   68   69   69   71   72

                72   73   74   76   77   77   78   79   80   81

                81   82   83   85   89   92   93   94   97   98

Work:

P56 = 40*56/100 = 22.4 as the 23^rd position; a 74 is in the 23^rd position.