A sociologist was hired by a large city hospital to investigate the relationship between the number of unauthorized days that employees are absent per year and the distance (miles) between home and work for the employees. A sample of 10 employees was chosen, and the following data were collected.  Use the estimated regression equation developed in part (c) to develop a 95% confidence interval for the expected number of days absent for employees living 5 miles from the company (to 1 decimal). Least squares equation from part c:
Days Absent = 7.269 + -0.194 Distance

A service station has both self-service and full-service islands. On each island, there is a single regular unleaded pump with two hoses. Let X denote the number of hoses being used on the self-service island at a particular time, and let Y denote the number of hoses on the full-service island in use at that time. The joint pmf of X and Y appears in the accompanying tabulation.

e.) What is E(Y|X=0)?

f.) What is Var(Y|X=0)?

l.) Standard deviation of X?

m.) Standard deviation of Y?

n.) Corr(X,Y)?

A national study report indicated that​ 20.9% of Americans were identified as having medical bill financial issues. What if a news organization randomly sampled 400 Americans from 10 cities and found that 95 reported having such difficulty. A test was done to investigate whether the problem is more severe among these cities. What is the​ p-value for this​ test? (Round to four decimal places.)

An urn contains 100 balls that have the numbers 1 to 100 painted on them (every ball has a distinct number). You keep sampling balls uniformly at random (i.e., every ball is equally likely to be picked), one at a time, and without replacement. For 1 ≤ i < j ≤ 100, let Ei,j denote the event that the ball with number j was picked after the ball with number i got picked. Identify which of the following sets of events are independent and which are not :

(a) E7,13 and E41,79

(b) E7,13 and E13,8

(c) (E7,13 ∩ E13,8) and E8,7

Please show work

A box in a supply room contains 15 compat fluorscent lightbulbs, of wich 5 are rated 13 watt, 6 are rated 18 watt, and 4 are rated 23 watt. Suppose that three bulbs are randomly slected.

a- What is the probablity that exactly two of the slected bullbs are rated 23 watt?

b- What is the probablity that all of the three slected bulbs have the same rating?

c- What is the probablity that one of each type is slected ?

Statistics from a public health nurse is provided below. Assist her in completing her report by determining the rate for

Each vital statistic based on the following information. If a rate cannot be calculated, note what is missing. Provide

The rate or information needed. For this county, the mid-year population is 500, 000 the estimated female

Note that all rates are multiplied by 1,000 except maternal mortality is a factor of 10, 000.

Available information for the year

To investigate water quality, in early September 2016, the Ohio Department of Health took water samples at 2424 beaches on Lake Erie in Erie County. Those samples were tested for fecal coliform, which is the E.coli bacteria found in human and animal feces. An unsafe level of fecal coliform means there is a higher chance that disease‑causing bacteria are present and more risk that a swimmer will become ill if she or he should accidentally ingest some of the water. Ohio considers it unsafe for swimming if a 100100‑milliliter sample (about 3.43.4 ounces) of water contains more than 400400 coliform bacteria. The E. colilevels found by the laboratories are shown in the table.

To access the complete data set, click the link for your preferred software format:

Excel  Minitab  JMP  SPSS TI  R  Mac-TXT   PC-TXT  CSV  CrunchIt!

Take these water samples to be an SRS of the water in all swimming areas in Erie County. Let ?μ represent the mean E. colicounts for all possible 100100‑mL samples taken from all swimming areas in Erie County. We test ?0:?=400 versus ??:?<400H0:μ=400 versus Ha:μ<400 because the researchers are interested in whether the average E. coli levels in these areas are safe.

(a) Find ?⎯⎯⎯x¯ , ?s , and the ?t statistic. (Enter your answers rounded to three decimal places)

?⎯⎯⎯=x¯=

?=s=

?=t=

Find the ?-valueP-value . (Enter your answer rounded to four decimal places.)

?‑value=P‑value=

Are these data good evidence that on average the E. coli levels in these swimming areas were safe?

There is not good evidence to conclude that swimming areas in Erie County have mean E. coli counts less than 400400 bacteria per 100100 mL.

The data gives us no conclusive evidence one way or the other.

There is good evidence to conclude that swimming areas in Erie County have mean E. coli counts less than 400400 bacteria per 100100mL.

(b) Use the software of your choice to make a graph of the data. The distribution is very skewed. Another method that gives?P‑values without assuming any specific shape for the distribution gives a ?P‑value of 0.00430.0043 to answer if the given data shows average E.coli levels were safe in the swimming areas.

How does the one‑sample ?t test compare with this?

The one‑sample ?t test gives a significantly higher ?P‑value.

Both methods give similar ?P‑values.

The one‑sample ?t test gives a significantly lower ?P‑value.

Should the ?t procedures be used with these data?

Due to extreme skew and the presence of outliers, ?t procedures should not be used here.

Due to symmetry and the absence of outliers, ?t procedures should be used here.

Due to symmetry and the absence of outliers, ?t procedures should not be used here.

What does the ?P‑value from the method that does not assume any specific shape for the distribution indicate?

The method that does not assume a specific shape for the distribution provides very little evidence that these swimming areas are safe on average.

The method that does not assume a specific shape for the distribution provides very strong evidence that these swimming areas are safe on average.

The method that does not assume a specific shape for the distribution provides very strong evidence that these swimming areas are not safe on average.

In case- control study, 185 women with endometriosis and 370 women without endometriosis were analyzed. The par- ticipants’ mean age was 35.21 years (SD: 7.09) in the case group and 35.28 years (SD: 7.03) in the control group. The two groups significantly were differed regarding the level of education; the percentage of participants with academic degrees in the case group was twice as high as those in the control group (P<0.001). Moreover, 32 (17.3%) women of the case group and 10 (2.7%) women of the control group were employed, again indicating a significant difference be- tween the two groups (P<0.001). However, the two groups were similar regarding the sufficiency of monthly income (P=0.698). The two groups were compared in a history of diseases such as diabetes, hypothyroidism, hypertension, cardiovascular diseases, cerebrovascular diseases, seizures and asthma, and did not show any significant differences (P=0.860). The two groups were also similar regarding an autoimmune disease history, e.g. rheumatoid arthritis, mul- tiple sclerosis, and lupus erythematosus (P=0.669). There were 38 (20.5%) women in the case group and 47 (12.7%) women in the control group with a history of allergies, in- dicating a significant difference between the two groups (P=0.016). Nevertheless, both groups were similar regard- ing the type of allergies (seasonal, food, drug, or skin) (P=0.946). In the case group 13 (7%) women reported a history of endometriosis in their mothers and sisters, and 7 (3.8%) women reported this in their aunts, while no woman in the control group reported a history of this disease in 
Int J Fertil Steril, Vol 13, No 3, October-December 2019 232 
her first-degree relatives, demonstrating a significant dif- ference between the groups (P<0.001). Only one woman in the control group had a history of smoking, and no one in either group had a history of alcohol use.

The results of the present study are consistent with the results of Samir’s group. Based on our findings, the risk of endometriosis is approximately five times higher in women who stated they had vaginal intercourse leading to orgasm during menstruation and three times higher in those with non-coital sexual activ- ity leading to orgasm during menstruation, compared to those who stated they did not. 

question

5. What are the findings of the study? Are these similar to what is already found in the field or are these new findings?

6. Did the graphs, tables and figures in the study clarify the results? Give specific examples.

Klaus is an office manager at a data entry company. He is interested in finding ways to improve employee productivity. Klaus wonders if the number of hours worked is related to productivity. To test this, he installs software on each of his employees’ computers that measures how many cells of data they enter and how long they work. The data are provided in Figure 12.34. By hand, using Excel, or using SPSS, conduct the full hypothesis testing procedure for his data and draw any appropriate conclusions.

2. You are a member of a group of researchers who study the reading ability of children. You would like to know if any of the following factors have an effect on the reading ability of a child: age, memory span, and IQ. You conduct a pilot study on a small group of 20 children. From the initial finding, you will make recommendations to your group on further research.

   Complete the regression analyses and answer the questions about the models on this paper. Copy and paste Excel output to show how you determined your answers.

   age	memory_span	IQ	reading_ability
   6.7	4.4	95	7.2
   5.9	4	90	6
   5.5	4.1	105	6
   6.2	4.8	98	6.6
   6.4	5	106	7
   7.3	5.5	100	7.2
   5.7	3.6	88	5.3
   6.15	5	95	6.4
   7.5	5.4	96	6.6
   6.9	5	104	7.3
   4.1	3.9	108	5
   5.5	4.2	90	5.8
   6.9	4.5	91	6.6
   7.2	5	92	6.8
   4	4.2	101	5.6
   7.3	5.5	100	7.2
   5.9	4	90	6
   5.5	4.2	90	5.8
   4	4.2	101	5.6
   5.9	4	90	6

3. Build a regression model using the variables as shown below. Review the results and determine which is the model is the “best”.

1. What is the ANOVA table of the model?

2. What is the regression equation of the model?

3. Conduct the test for the significance of the Overall Regression Model for the model?

4. What is R² of the best model?

5. What are the 95% confidence intervals for the estimates of the regression coefficients—the B_i’s?

6. Provide an interpretation of the slopes, b_i’s.

3. Select one model you would use to explain reading ability. Then use that model to find the

• 95% confidence interval estimate for the mean reading ability
• 95% prediction interval for reading ability

When age = 6, mem_span = 4.2 and IQ = 91.

Which model did you select and why?

How does confidence internals confirm hypothesis testing results. Provide an example

. The average wind speed in Casper, WY, has been found to be 12.7 mph, and in Phoenix, AZ, it is 6.2 mph. To test the relationship between the averages, the average wind speed was calculated for a sample of 31 days for each city. The results are reported below. (15 pts)

Is there sufficient evidence at α = 0.05 to conclude that the average wind speed is greater in Casper than in Phoenix? Complete the hypotheses H_1, a summary of your answer, and draw the normal curve.

H₀: μ₁ = μ₂                         α = 0.05           C.V. = ________

H₁: μ₁    μ₂ (claim)

Post a situation in which it might be interesting to know whether a difference in variances exists. Why would it be important to know if a difference exists. What actions might result if differences are or aren't found?

"Durable press" cotton fabrics are treated to improve their recovery from wrinkles after washing. Unfortunately, the treatment also reduces the strength of the fabric. The breaking strength of untreated fabric is normally distributed with mean 52.5 pounds and standard deviation 2.4 pounds. The same type of fabric after treatment has normally distributed breaking strength with mean 29.9 pounds and standard deviation 1.6 pounds. A clothing manufacturer tests 5 specimens of each fabric. All 10 strength measurements are independent. (Round your answers to four decimal places.) (a) What is the probability that the mean breaking strength of the 5 untreated specimens exceeds 50 pounds? (b) What is the probability that the mean breaking strength of the 5 untreated specimens is at least 25 pounds greater than the mean strength of the 5 treated specimens?