Construct a histogram of your empirical data using eight bars and then five bars. For consistency's sake, for eight bars use the class width of 0.125. So, your first bar will be 0.000-0.124, your next bar will be 0.125 - 0.249, etc. For five bars, use the class width of 0.2. So, your first bar will be 0.00-0.19, your next bar will be 0.2-0.39, etc. Upload both pictures of your histograms. ***Below are my 50 random numbers. What do I need to show? I am confused on what exactly I need to show. Can you help me on these?

0.9          1.0          0.7          0.0          0.8         

0.0          0.8          0.2          0.0          1.0

0.5          0.2          0.5          0.4          0.0

0.8          0.1          0.4          0.2          1.0

0.1          0.1          0.9          0.7          0.1

0.9          1.0          0.9          0.2          0.4

0.0          1.0          0.5          0.9          0.4

0.9          0.0          0.0          1.0          0.3

0.4          0.8          0.9          0.6          0.5

0.4          0.5          0.3          0.7          1.0

A rural county hospital offers several health services. The hospital administrators conducted a poll to determine whether the residents’ satisfaction with the available services depends on their gender. A random sample of 1000 adult county residents was selected. The gender of each respondent was recorded and each was asked whether he or she was satisfied with the services offered by the hospital. The resulting data are shown in the table below. Using a significance level of 0.05, conduct an appropriate test to determine if, for adult residents of this county, there is an association between gender and whether or not they were satisfied with services offered by the hospital.

Adam tabulated the values for the average speeds on each day of his road trip as 60.5, 63.2, 54.7, 51.6, 72.3, 70.7, 67.2, and 65.4 mph he wishes to construct a 98% confidence interval what value of t* should Adam use to construct the confidence interval?

Dr. Patel is concerned about the long wait times in his office. The following table presents six random observations for the patient waiting times over a period of 10 days.

1. Dr. Patel is willing to use three-sigma limits. Use the given data and the factors from Table 3.1 (page 110) to construct R-chart and -chart.
2. Is the process in statistical control? Explain.
3. If patient surveys indicate that they are willing to wait between 10 and 30 minutes before seeing Dr. Patel, is the process capable of meeting this demand at the three-sigma level?

Table 3.1

Factors For Calculating Three Sigma Limits for the x¯x¯ -Chart and R-Chart

A random sample of 15 chemists from Washington state shows an average salary of $46613 with a standard deviation of $775. A random sample of 24 chemists from Florida state shows an average salary of $47757 with a standard deviation of $872. A chemist that has worked in both states believes that chemists in Washington make a different amount than chemists in Florida. At α α =0.01 is this chemist correct? Let Washington be sample 1 and Florida be sample 2. The correct hypotheses are: H 0 : μ 1 ≤ μ 2 H 0 : μ 1 ≤ μ 2 H A : μ 1 > μ 2 H A : μ 1 > μ 2 (claim) H 0 : μ 1 ≥ μ 2 H 0 : μ 1 ≥ μ 2 H A : μ 1 < μ 2 H A : μ 1 < μ 2 (claim) H 0 : μ 1 = μ 2 H 0 : μ 1 = μ 2 H A : μ 1 ≠ μ 2 H A : μ 1 ≠ μ 2 (claim) Correct

Since the level of significance is 0.01 the critical value is 2.736 and -2.736

The test statistic is: Incorrect(round to 3 places)

The p-value is: Incorrect(round to 3 places)

A custodian wishes to compare two competing floor waxes to decide which one is best. He believes that the mean of WaxWin is less than the mean of WaxCo.

In a random sample of 12 floors of WaxWin and 16 of WaxCo. WaxWin had a mean lifetime of 25.5 with a standard deviation of 6.7 and WaxCo had a mean lifetime of 30.4 with a standard deviation of 10.6. Perform a hypothesis test using a significance level of 0.05 to help him decide.

Let WaxWin be sample 1 and WaxCo be sample 2

The correct hypotheses are:

• H0:μ1≤μ2H0:μ1≤μ2
  HA:μ1>μ2HA:μ1>μ2(claim)
• H0:μ1≥μ2H0:μ1≥μ2
  HA:μ1<μ2HA:μ1<μ2(claim)
• H0:μ1=μ2H0:μ1=μ2
  HA:μ1≠μ2HA:μ1≠μ2(claim)

Since the level of significance is 0.05 the critical value is -1.707
The test statistic is: (round to 3 places)
The p-value is: (round to 3 places)

A researcher is interested in seeing if the average income of rural families is greater than that of urban families. To see if his claim is correct he randomly selects 20 families from a rural area and finds that they have an average income of $66691 with a standard deviation of $794. He then selects 12 families from a urban area and finds that they have an average income of $69126 with a standard deviation of $978. Perform a hypothesis test using a significance level of 0.01 to help him decide.

Let the rural families be sample 1 and the urban families be sample 2.

The correct hypotheses are:

• H0:μ1≤μ2H0:μ1≤μ2
  HA:μ1>μ2HA:μ1>μ2(claim)
• H0:μ1≥μ2H0:μ1≥μ2
  HA:μ1<μ2HA:μ1<μ2(claim)
• H0:μ1=μ2H0:μ1=μ2
  HA:μ1≠μ2HA:μ1≠μ2(claim)

Since the level of significance is 0.01 the critical value is 2.532
The test statistic is: (round to 3 places)
The p-value is: (round to 3 places)

You may need to use the appropriate appendix table or technology to answer this question.

A simple random sample of 60 items resulted in a sample mean of 90. The population standard deviation is

σ = 15.

(a)

Compute the 95% confidence interval for the population mean. (Round your answers to two decimal places.)

( )to( )

(b)

Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean. (Round your answers to two decimal places.)

( )to( )

(c)

What is the effect of a larger sample size on the interval estimate?

A. A larger sample size does not change the margin of error.

B. A larger sample size provides a smaller margin of error.    

C. A larger sample size provides a larger margin of error.

Suppose that there are 100 students entering the Master’s of Business Administration program. Of these students, 20 have two years of work experience, 30 have three years of work experience, 15 have four years of work experience, and 35 have five or more years of work experience.

a) One of the students is selected at random. What is the probability that this student has at least three years of work experience?

b) The selected student has at least three years of work experience. What is the probability the student has four years of work experience?

c) Three students are selected at random. Calculate the probability that all three students have five or more years of work experience. Describe the key assumption required to make the calculation and comment on whether the assumption is reasonable.

d) Would it be reasonable to use the probability calculated in part a) as an estimate of the proportion of students entering the MBA degree program who have at least three years of work experience? Explain your answer. Limit your explanation to at most five sentences.

Consider a sample of size 100 drawn from a population that obeys an unknown distribution. It is known that the population-variance (of some quality characteristic) is 6. Let µ denote the population-mean. Consider the following test of a hypothesis about µ.

H₀ : µ = 70

H₁ : µ ≠ 70

(a) Calculate Z_0.005. Explain the meaning of Z_0.005. (b) If the sample mean is observed to be 71, would you reject H₀ with 99% confidence? What is the p-value of the sample mean? (c) If the sample mean is observed to be 71, and the sample size is 30 (instead of 100), would you reject H₀ with 99% confidence?

HIV-related deaths and mid-year population by age group in Country Y in 2003 are given below

(d) Calculate the age-specific HIV-related death rates for country Y in 2003, and complete the above table. (4pts)

(e) Can you conclude that a person living in country X has a risk of dying from HIV that is 1.2 times as high as a person living in country Y? Give a reason for your answer (2pts)

Our event of interest is whether a defective chip is found in a set of chips, and let Y be the number of chips that must be sampled until a defective one is found. The researchers estimate the probability of a defective chip at 30%. What is the probability that the 8th selected chip be the first defective one?

Consider the following time series data:

A city council suspects a judge of being a "hanging judge" because s/he is perceived as imposing harsher penalties for the same sentence. To investigate this, a random sample of 45 cases is taken from the judge's prior cases that resulted in a guilty verdict for a certain crime. The average jail sentence s/he imposed for the sample is 25 months. The average jail sentence for the same type of crimes is 23 months with a standard deviation of 13 months. What can be concluded with α = 0.01?

What is the appropriate test statistic?
---Select--- na

z-test

one-sample t-test

independent-samples t-test

related-samples t-test

Compute the appropriate test statistic(s) to make a decision about H₀.
(Hint: Make sure to write down the null and alternative hypotheses to help solve the problem.)
critical value =   ; test statistic =  

If appropriate, compute the CI. If not appropriate, input "na" for both spaces below.
[   ,   ]

e) Compute the corresponding effect size(s) and indicate magnitude(s).
If not appropriate, input and select "na" below.
d =   ;   ---Select--- na trivial effect small effect medium effect large effect
r² =   ;   ---Select--- na trivial effect small effect medium effect large effect

This investigation will involve measuring how high people can jump. Use of tools, such as tape measures and rulers, should be considered.

1. Collect data.

2. Calculate the means and the five-number summaries for the entire sample and for each of your categories of the qualitative variable (e.g., for male and for female) and make a chart that presents those statistics.

3. Create comparative boxplots for the different groups (e.g., male and female).

4. Describe where your own jump-height falls in relation to your data sets. Use measures of position such as percentile and quartile.

5. Consider jump-heights and the qualitative variable you have chosen. Discuss and determine which should be the independent and which should be the dependent variable. Then create a scatterplot.  

The data can be made up, but please make it accurate (dont say that a person jumped a mile in height). Let the sample size be at least 10.

1.Which of the following scenarios would it be appropriate to use a normal approximation for the sampling distribution of the sample proportion?

Select one:

a.) A researcher wishes to find the probability that more than 60% of a sample of undergraduate students from UNC will be female. She samples the first 42 students that walk into the gym on Monday morning. The population proportion of undergraduate females at UNC is known to be 60.1%.

b.)A researcher wishes to find the probability that less than 5% of a sample of undergraduate students from Appalachian State University will be between the ages of 25 and 34. He randomly samples 50 undergraduate students from the student database. The proportion of undergraduates between the ages of 25 and 34 is 5.3%.

c.)A grad student at NC state wants to know how likely it is that a group of students would be made up of more than 27% graduate students. She will randomly select 38 students and ask them if they are a graduate student or an undergraduate student. The population proportion of grad students at NC state is 26.6%.

d.)A full-time student at Fayetteville State University wants to know how likely it is that a group of students would be made up of less than 70% full-time students. She will ask 30 people that she sees parking in the parking deck if they are full-time or part-time. The population of full-time students at Fayetteville State is known to be 72%.

2. In the general population in the US, identical twins occur at a rate of 30 per 1,000 live births. A survey records 10,000 births during Jan 2018 to Jan 2019 and found 400 twins in total. Which of the following are true?

Select one or more:

The proportion of twin births during Jan 2018 to Jan 2019 is .03.

The proportion of twin births during Jan 2018 to Jan 2019 is .04.

The probability of twin births among the general population is .03.

The probability of twin births among the general population is .04.

Pr(observing a sample proportion of twin births from a random sample of 10,000 live births <= 0.04) = 0.03.

Pr(observing a sample proportion of twin births from a random sample of 10,000 live births <= 0.04) = 0.5.

Pr(observing a sample proportion of twin births from a random sample of 10,000 live births <= 0.03) = 0.04.

Pr(observing a sample proportion of twin births from a random sample of 10,000 live births <= 0.03) = 0.5.

Twenty-nine percent of primary care doctors think their patients receive unnecessary medical care. If required, round your answer to four decimal places. (a) Suppose a sample of 300 primary care doctors was taken. Show the distribution of the sample proportion of doctors who think their patients receive unnecessary medical care.