The Human Resource department of a multi-national bank is preparing a survey about workplace equality. The survey will target employees of three departments: retail banking, commercial banking, and global banking. There are 1800, 2300, and 900 employees in these departments respectively. A total of 200 employees will be selected randomly for the survey.
The following table shows the number of weekly working hours of 14 employees in a sample dataset: 38 41 41 43 46 48 49 51 54 54 57 64 64 64
(d) Find the 30th percentile and third quartile of the data.
(e) Write a simple report about the weekly working hours of the employees by referring to your findings in part (c) and part (d).
(f) The standard working hour per week is 40 hours. Every extra working hour would have an hourly allowance of $35. Use X to denote the weekly working hour of an employee and Y to denote the weekly allowance of that employee. Express Y in terms of X. Hence, find the sample mean and sample standard deviation of the weekly allowance of an employee.
In: Statistics and Probability
In: Statistics and Probability
resistant. To find the 10% trimmed mean for a
data set, first arrange the data in order, then delete
the bottom 10% of the values and delete the top 10% of
thevalues, then calculate the mean of the remaining values. Use
the axial loads (pounds) of aluminum cans listed below for
cans that are 0.0111 in. thick. Identify anyoutliers, then compare
the median, mean, 10% trimmed mean, and 20%
trimmed mean.
247247
261261
269269
272272
275275
279279
280280
284284
285285
285285
285285
288288
289289
292292
292292
295295
295295
300300
311311
504504
Identify any outliers. Select the correct choice
below and, if necessary, fill in the answer box to
complete your choice.
A.
The outlier(s) is/are
nothing
pounds.
(Type a whole number. Use a comma to separate answers as needed.)
B.
There are no outliers.
The median is
nothing
pounds.
(Type an integer or decimal rounded to one decimal place as needed.)
The untrimmed mean is
nothing
pounds.
(Type an integer or decimal rounded to one decimal place as needed.)
The 10% trimmed mean is
nothing
pounds.
(Type an integer or decimal rounded to one decimal place as needed.)
The 20% trimmed mean is
nothing
pounds.
(Type an integer or decimal rounded to one decimal place as needed.)
Compare the values. Choose the correct answer below.
A.
The median, untrimmed mean, and 10% trimmed mean are close to each other. However, the 20% trimmed mean is significantly different from those values.
B.
The median, untrimmed mean, and 20% trimmed mean are close to each other. However, the 10% trimmed mean is significantly different from those values.
C.
All of the values are close to each other.
D.
The untrimmed mean, 10% trimmed mean, and 20% trimmed mean are close to each other. However, the median is significantly different from those values.
E.
The median, 10% trimmed mean, and 20% trimmed mean are close to each other. However, the untrimmed mean is significant
In: Statistics and Probability
In a simple random sample of 1600 young people, 86% had earned a high school diploma. Complete parts a through d below. a. What is the standard error for this estimate of the percentage of all young people who earned a high school diploma? .0096 nothing (Round to four decimal places as needed.) b. Find the margin of error, using a 95% confidence level, for estimating the percentage of all young people who earned a high school diploma. nothing% (Round to one decimal place as needed.) c. Report the 95% confidence interval for the percentage of all young people who earned a high school diploma. left parenthesis nothing % comma nothing % right parenthesis (Round to one decimal place as needed.) d. Suppose that in the past, 80% of all young people earned high school diplomas. Does the confidence interval you found in part c support or refute the claim that the percentage of young people who earn high school diplomas has increased? Explain. A. The interval does not support this claim. This is because 80% is not in the interval, and all values are above 80%. B. The interval supports this claim. This is because 80% is not in the interval, and all values are above 80%. C. The interval does not support this claim. This is because 80% is in the interval. D. The interval supports this claim. This is because 80% is in the interva
In: Statistics and Probability
The National Study of the Changing Work Force has just completed an extensive survey of 2958 wage and salaried workers on issues ranging from relationships with their bosses to household chores. The data were gathered through hour-long telephone interviews with a nationally representative sample (The Wall Street Journal). In response to the question “What does success mean to you?” 1538 responded, “Personal satisfaction from doing a good job.”
Based on your professional skills in statistical analysis, you have just been hired to help with an analysis and interpretation of this survey.
If p be the population proportion of all wage and salaried workers who would respond the same way to the stated question, what would be the 80% (or 90% or 95% or 99%) confidence interval for p.
Make sure that you show your computations.
Complete the following table:
Confidence Interval |
The interval |
80% |
< p < |
90% |
< p < |
95% |
< p < |
99% |
< p < |
In: Statistics and Probability
A study was done using a treatment group and a placebo group. The results are shown in the table. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Use a 0.10 significance level for both parts
Treatment Placebo
μ μ1 μ2
n 27 40
x 2.38 2.61
s 0.68 0.99
a. Test the claim that the two samples are from populations with the same mean.
What are the null and alternative hypotheses?
A. H0: μ1≠μ2
H1: μ1<μ2
B. H0: μ1=μ2
H1: μ1≠μ2
C. H0: μ1<μ2
H1: μ1≥μ2
D. H0: μ1=μ2
H1: μ1>μ2
The test statistic, t, is _____. (Round to two decimal places as needed.)
The P-value is _____. (Round to three decimal places as needed.)
State the conclusion for the test.
A. Fail to reject the null hypothesis. There is sufficient evidence to warrant rejection of the claim that the two samples are from populations with the same mean.
B. Reject the null hypothesis. There is sufficient evidence to warrant rejection of the claim that the two samples are from populations with the same mean.
C. Reject the null hypothesis. There is not sufficient evidence to warrant rejection of the claim that the two samples are from populations with the same mean.
D. Fail to reject the null hypothesis. There is not sufficient evidence to warrant rejection of the claim that the two samples are from populations with the same mean.
b. Construct a confidence interval suitable for testing the claim that the two samples are from populations with the same mean.
_____<μ1−μ2< _____
(Round to three decimal places as needed.)
In: Statistics and Probability
Mitchell and Cameron have two adopted children. We are interested in the biological sex (Male/Female) of their children.
(a)[3 pts] Give the sample space for thesex of their two children.1 full point out of the 3will be for using the correct format.
(b)[2 pts] What is the probability that both children are girls, given that the first child is a girl? You do not have to show a lot of mathematical work for this, but the more work you show, the more partial credit you may get if your answer is wrong.
(c)[3 pts] We ask Mitchell: “Do you guys have at least one daughter?”He responds: “Yes!” Knowing that Mitch & Cam have at least one daughter, what is the probability now that both children are girls?
Thank u
In: Statistics and Probability
Is it possible to predict the annual number of business bankruptcies by the number of firm births (business starts)? The following table shows the number of business bankruptcies (1,000s) and the number of firm births (10,000s) for a six-year period. Use these data to develop the equation of the regression model to predict the number of business bankruptcies by the number of firm births. Discuss the meaning of the slope.
Business Bankruptcies (1,000s) |
Firm Births (10,000s) |
34.8 | 58.1 |
35.0 | 55.8 |
38.5 | 57.0 |
39.8 | 58.5 |
35.5 | 57.4 |
37.9 | 58.0 |
r =
The r value represents a relatively :
strong positive, strong negative , moderate positive or moderate negative. (choose one)
relationship between the number of firm births and the number of business bankruptcies.
Y is ________________ + X is _______________________
The slope of the line means that for every 10,000 increase of firm births, the number of business bankruptcies is predicted to increase by ______________
.
In: Statistics and Probability
Data from a recent year showed that 72% of the tens of thousands of applicants to a certain program were accepted. A company that trains applicants claimed that 216 of the 280 students it trained that year were accepted. Assume these trainees were representative of the population of applicants. Has the company demonstrated a real improvement over the average? Find z score
In: Statistics and Probability
Suppose that a category of world class runners are known to run
a marathon (26 miles) in an average of 146 minutes with a standard
deviation of 12minutes. Consider 49 of the races.
Let X = the average of the 49 races.
a)Give the distribution of X. (Round your standard deviation to two decimal places.)
X~___(___,___)
b)Find the probability that the average of the sample will be between 145 and 148 minutes in these 49 marathons. (Round your answer to four decimal places.)
_________
c) Find the 70th percentile for the average of these 49 marathons. (Round your answer to two decimal places.)
_____min
d) Find the median of the average running times.
____min
In: Statistics and Probability
Heine Brothers’, a coffee shop chain from Louisville, Kentucky, wants to determine if the amount of time customers spend in the “Germantown” coffee shop is different from the “Crescent Hill” coffee shop. An employee at each location times the amount of time 20 customers spends in each coffee shop. For the “Germantown” location the sample mean is 56.70 minutes with a sample standard deviation of 13.48 minutes. For the “Crescent Hill” location, the sample mean is 77.25 minutes with a standard deviation of 37.06 minutes.
In: Statistics and Probability
a1) If a researcher wanted to test which fever reducer between Tylenol and ibuprofen work faster. What should they do? Describe very clearly the process all the way down to what the p-value would tell you.
a2) Describe very clearly what pooling the variance assumes.
In: Statistics and Probability
Student |
Condition A |
Condition B |
1 |
68 |
69 |
2 |
87 |
88 |
3 |
61 |
65 |
4 |
59 |
63 |
5 |
85 |
92 |
6 |
68 |
67 |
7 |
67 |
78 |
8 |
48 |
53 |
In: Statistics and Probability
A mango Supply and Demand for a tropical country are given by ;
Demand: P = 50 – (QD) and supply: P = 25 + (QS) where QD = quantity demanded of mangoes and QS = quantity supplied of mangoes
Price |
Quantity Supplied |
Quantity Demanded |
0 |
0 |
12 |
200 |
2 |
10 |
400 |
4 |
8 |
600 |
6 |
6 |
800 |
8 |
4 |
1000 |
10 |
2 |
1200 |
12 |
0 |
The government decides to impose a price floor of $750. Illustrate graphically the different economics effects of such intervention in this market.
Compute the deadweight loss generated by the government intervention and the producer surplus.
Assume that the government levied a $25 tax on the consumers of steel. Illustrate graphically the different economics effects of the tax.
In: Statistics and Probability
Question 2: (Marks: 2)
Intelligence quotients (IQs) on the Stanford-Binet intelligence test are normally distributed with a mean of 100 and a standard deviation of 16. In Exercises a–d, use the 68–95–99.7 Rule to find the percentage of people with IQs
In: Statistics and Probability