In: Statistics and Probability
I mostly need questions 4-9, thank you!
NOTE: For question 1, you will be using the data file your
instructor has provided you.
Coin |
7 |
6 |
4 |
6 |
4 |
6 |
4 |
6 |
4 |
4 |
3 |
5 |
5 |
6 |
3 |
3 |
5 |
6 |
3 |
7 |
5 |
2 |
6 |
6 |
6 |
3 |
3 |
7 |
2 |
4 |
6 |
5 |
6 |
6 |
7 |
NOTE: for questions 2-7, you will NOT be using the data file your instructor gave you. Please follow the instructions given in each question.
3.(11 pts) List the probability value for each possibility in
the binomial experiment calculated at the beginning of this lab,
which was calculated with the probability of a success being ½.
(Complete sentences not necessary; round your answers to three
decimal places.)
P(x=0)
P(x=1)
P(x=2)
P(x=3)
P(x=4)
P(x=5)
P(x=6)
P(x=7)
P(x=8)
P(x=9)
P(x=10)
4. (12 pts) Give the probability for the following based on the
calculations in question 3 above, with the probability of a success
being ½. (Complete sentences not necessary; round your answers to
three decimal places.)
P(x≥1)
P(x>1)
P(3<x ≤7)
P(x<0)
P(x≤3)
P(x<3 or x≥7)
5. Calculate (by hand) the mean and standard deviation for the
binomial distribution with the probability of a success being ½ and
n = 10. Either show your work or explain how your answer was
calculated. Use these formulas to do the hand calculations: Mean =
np, Standard Deviation =
Mean =
Standard Deviation =
6. (7 pts) Calculate (by hand) the mean and standard deviation for
the binomial distribution with the probability of a success being ¼
and n = 10. Write a comparison of these statistics to those from
question 5 in a short paragraph of several complete sentences. Use
these formulas to do the hand calculations: Mean = np,
Standard Deviation =
Mean =
Standard Deviation =
Comparison:
7. Calculate (by hand) the mean and standard deviation for the
binomial distribution with the probability of a success being ¾ and
n = 10. Write a comparison of these statistics to those from
question 6 in a short paragraph of several complete sentences. Use
these formulas to do the hand calculations: Mean = np,
Standard Deviation =
Mean =
Standard Deviation =
Comparison:
8. Using all four of the properties of a Binomial experiment (see
page 201 in the textbook) explain in a short paragraph of several
complete sentences why the Coin variable from the class survey
represents a binomial distribution from a binomial
experiment.
9.(7 pts) Compare the mean and standard deviation for the Coin
variable (question 1) with those of the mean and standard deviation
for the binomial distribution that was calculated by hand in
question 5. Explain how they are related in a short paragraph of
several complete sentences.
Mean from question #1:
Standard deviation from question #1:
Mean from question #5:
Standard deviation from question #5:
Comparison and explanation:
3)
Sample size , n = 10
Probability of an event of interest, p = 0.5
Binomial probability is given by |
P(X=x) = C(n,x)*px*(1-p)(n-x) |
X | P(X) |
0 | 0.001 |
1 | 0.010 |
2 | 0.044 |
3 | 0.117 |
4 | 0.205 |
5 | 0.246 |
6 | 0.205 |
7 | 0.117 |
8 | 0.044 |
9 | 0.010 |
10 | 0.001 |
4)
P(x≥1)=0.9990
P(x>1)=0.989
P(3<x ≤7)=0.773
P(x<0)=0
P(x≤3)=0.172
P(x<3 or x≥7)=0.227
5)
Mean = np = 10*0.5=
5.000
Standard deviation = √(np(1-p)) =
√(10*0.5*(1-0.5))= 1.5811
6)
Mean = np = 10*0.25=
2.500
Standard deviation = √(np(1-p)) =
√(10*0.25*(1-0.25))=
1.3693
7)
Mean = np = 10*0.75=
7.500
Standard deviation = √(np(1-p)) =
√(10*0.75*(1-0.75))=
1.3693
8)
coin variable-
it is a binomial probability distribution,
because there is fixed number of trials,
only two outcomes are there, success and failure (head or
tail)
trails are independent of each other
The probability of "success" p is the same for each
outcome.