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Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 187228: /the probability that a married man watches a certain TV show is 0,4and the probability taht a married mwoman watches the show is 0.5. The probability that a man watches the show agiven that his wife watches it is 0.7. Find the probabiltiyt that a married couple watches the show; a wife watches the show given that her husband does; and at least one person of a married c ouple will watch the show.
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Question 187196: A box of chocolates contains 20 identically shaped chocolates. Five of them are filled with jelly, three are filled with caramel, and twelve are filled with nuts. What is the probability that one chocolate chosen at random is filled with jelly, caramel or nuts?
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Question 187177: A study of iron deficiency among infants compared samples of infants following different feeding regimens. One group contained breast-fed infants, while the children in other group were fed a standard baby formula without any iron supplements. Here are summary results on blood hemoglobin levels at 12 months of age.
Group n Mean s
Breast-fed 23 13.3 1.7
Formula 19 12.4 1.8
a.) Is there significant evidence that the mean hemoglobin level is higher among breast-fed babies? State null hypothesis and alternate hypothesis and conduct at –test.
b.) Give a 95% confidence interval for the mean difference in hemoglobin level between the two populations of infants.
qus 2
A small accounting firm pays each of its five clerks Rs 25000, two junior accountants Rs 60000, and the firm‘s owner Rs 255000. What is the mean salary paid at this Firm? How many of the employees earn less than the mean? What is the median salary?
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Question 187153: I NEED HELP IN STATISTICS. PLEASE HELP. THANK YOU SO MUCH.
At mississippi University, a sample of 18 senior accounting majors showed a mean cumulative GPA of 3.35 with a standard deviation of 0.25. At α = .05 in a two-tailed test, does this differ significantly from 3.25 (the mean GPA for all business school seniors at the university)? Explain your decision on the null hypothesis
Hypothesis Test: Mean vs. Hypothesized Value
3.2500 hypothesized value
3.3500 mean problem4
0.2500 std. dev.
0.0589 std. error
18 n
17 df
1.70 t
.1079 p-value (two-tailed)
3.2257 confidence interval 95.% lower
3.4743 confidence interval 95.% upper
0.1243 half-width
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Question 187151: I NEED HELP IN STATISTICS. PLEASE HELP. THANK YOU SO MUCH.
Quality Polls contends that an agent conducts a mean of 53 in-depth home surveys every week. A streamlined survey form has been introduced, and the pollster wants to evaluate its effectiveness. A random sample of 17 agents showed their total number of surveys conducted during a week.
58
58
63
48
51
54
59
57
56
59
53
51
53
54
64
59
60
At the .05 level of significance, can we conclude that the mean number of interviews conducted by the agents is more than 53 per week? Why? Explain your decision on the null hypothesis.
Hypothesis Test: Mean vs. Hypothesized Value
53.000 hypothesized value
56.882 mean Data
3.199 std. dev.
0.776 std. error
17 n
16 df
5.00 t
.0001 p-value (one-tailed, upper)
55.237 confidence interval 95.% lower
58.527 confidence interval 95.% upper
1.645 half-width
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Question 187287: I am having some trouble with my statistics homework. I hope some one can please help.
Hypothesis Testing for the Mean (Large Samples)
Use the guidelines at the end of the project.
1.Convicted murderers receive a sentence of an average of 18.7 years in prison. A criminologist wants to perform a hypothesis test to determine whether the mean sentence by one particular judge differs from 18.7 years. A random sample of 40 cases from the court files from this judge is taken. It is found that sample mean is 17.2 years. Assume that the population standard deviation is 7.4 years. Test at the 0.05 significance level.
a.) Use the critical value z0 method from the normal distribution.
1.H0:
Ha:
2.alpha =
3.Test statistics:
P-value or critical z0 or t0.
4.Rejection Region:
5.Decision:
6.Interpretation:
b) Use the P-value method.
1.H0:
Ha:
2.alpha=
3.Test statistics:
P-value or critical z0 or t0.
4.Rejection Region:
5.Decision:
6.Interpretation:
Hypothesis Testing for Mean (Small Samples)
2. Metro Bank claims that the mean wait time for a teller during peak hours is less than 4 minutes. A random sample of 20 wait times has a mean of 2.6 minutes with a sample standard deviation of 2.1 minutes.
a. Use the critical value z0 method from the normal distribution to test for the population mean . Test the company’s claim at the level of significance alpha = 0.05. 1.H0 :
Ha :
2.alpha =
3.Test statistics:
P-value or critical z0 or t0.
4.Rejection Region:
5 Decision:
6 Interpretation:
b.) Use the critical value z0 method from the normal distribution to test for the population mean . Test the company’s claim at the level of significance alpha= 0.01
1.H0 :
Ha :
2.alpha =
3.Test statistics:
4.P-value or critical z0 or t0.
5.Rejection Region:
6.Decision:
7.Interpretation:
I would like to thank you in advance for useing your free time to help me with these problems.
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Question 187149: PLEASE HELP. I NEED HELP IN STATISTICS. THANK YOU SO MUCH
The Web-based company gift baskets galore! Gifts have a goal of processing 95 percent of its orders on the same day they are received. If 570 out of the next 600 orders are processed on the same day, would this prove that they are exceeding their goal, using α = .05? Explain your decision. clearly state your decision on the null hypothesis.
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Question 187146: I NEED HELP. PLEASE HELP ME SOLVE THIS. THANK YOU SO MUCH
9.54 Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 75 randomly chosen fax transmissions during the next year, yielding a sample mean of 11.44 with a standard deviation of 2.15 pages. At the .05 level of significance, is the true mean greater than 10? Explain your decision.
Clearly state your decision on the null hypothesis.
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Question 187334: Seven girls and six boys walk into a video store. There are five salespeople available to help them. Find the probability that the salespeople will first help the given numbers of girls and boys.
P(4 girls or 4 boys)
P(all girls or all boys)
P(at least 4 girls or at least 4 boys)
(Sorry, I don't have the ISBN but it's on page 661 of Adding Probablilites of the www.algebra2.com book http://www.glencoe.com/sec/math/algebra/algebra2/algebra2_05/ )
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Question 187634: I have a question about my statistics homework, can someone please help me. Thank you.
Hypothesis Testing for Proportions.
1. In a recent poll, it was found that 43% of registered U.S. voters would vote for the incumbent president. If 100 registered voters were sampled randomly, it was found that 35% would vote of the incumbent. Actual proportion is 43% test the claim at the level of significance alpha = 0.01
1.H0 :
Ha :
2.alpha =
3.Test statistics:
4.P-value or critical z0 or t0.
5.Rejection Region:
6.Decision:
7.Interpretation:
I would like to thank you in advance for your help and useing your time to help me.
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Question 187760: I have a problem in my statistics home work. I ask this question before but I missed a very important part.Here is the whole question:
In a recent poll it was found that 43% of registered U.S. voters would vote for the incumbent president. If 100 registered voters were sampled randomly, it was found that 35% would vote of the incumbent. Test the claim that the actual proportion is 43% the level of singifiance is 0.01
Ho:
Ha:
alpha=
Test statistics:
P-value or critical Zo or to.
Rejection region:
Decision:
Interpretation:
I would like to thank you in advance for your help.
Click here to see answer by stanbon(26259) |
Question 187806: From National Weather Service records, the annual snowfall in the TopKick Mountains has a mean of 92 inches and a standard deviation of 12 inches. If the snowfall from 36 randomly selected years are chosen, what it the probability that the snowfall would be less than 95 inches?
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Question 187831: A license plate is to consist of two letters followed by three digits. How many different license plates are possible if the first letter must be a vowel, and repetition of letters is not permitted, but repetition of digits is permitted?
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Question 187898This question is from textbook Elementary statistics
: 13.) Of the total population of older Americans, 18% live in Florida. For a randomly selected sample of 200 older Americans, find the probability that more than 40 live in Florida.
This is my work p=0.18 q= 0.82 and n=200
np= (2000(0.18)=36 nq=(200)(0.82)=164
square root of npq= square root of 29.52= 5.43
p(x>40)
then im not sure what is next please help me with this problem. Thanks!This question is from textbook Elementary statistics
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