To improve turnover (employees leaving your organization), you implemented a new training program company-wide about a year ago. However, you're not sure that the training is equally effective in reducing turnover between your service department, sales departments, and warehouse. To test this, you retrieved a list of all current and former employees that have received the training and created a dataset also recording their department. Conduct a test of independence to investigate this.

Turnover: Department:

former warehouse

current service

current sales

former warehouse

current sales

former sales

current sales

current service

former warehouse

current sales

current service

current warehouse

current service

current warehouse

current service

former sales

former sales

former service

The p-value for this chi-square was _____________and the chi-square value was _______________. This test _____________ achieve statistical significance. The expected value for Former Employee/Service was_________________, while the observed value was _______________________

options to fill in the blanks:

0.03, did, 2.33, did not, 0.33, 2.23, 1, 1.98.

The commercial division of a real estate firm conducted a study to determine the extent of the relationship between annual gross rents ($1000s) and the selling price ($1000s) for apartment buildings. Data were collected on several properties sold. The data is...

(a) How many apartments are there?
(b) Write the estimated regression equation
(c) Use the t-test to determine whether the selling price is related to annual gross rents. Use a=0.05
(d) Use the f-test to determine whether the selling price is related to annual gross rents. Use a=0.05
(e) Predict the selling price of an apartment building with gross annual rents of $52500

For each of the following situations, explain whether the binomial distribution applies for X.

a. You are bidding on four items available on eBay. You think that you will win the first bid with probability 25% and the second through fourth bids with probability 30%. Let X denote the number of winning bids out of the four items you bid on.

b. You are bidding on four items available on eBay. Each bid is for $70, and you think there is a 25% chance of winning a bid, with bids being independent events. Let X be the total amount of money you pay for your winning bids.

In a question involving a hypothesis test having the population mean as the target parameter, you are given the sample size, n, the assumed population mean, the significance of the test, alpha, whether it is a right-tailed, left-tailed, or two-tailed test, and the result of the test (reject or do not reject the null hypothesis.)

Show how you can use this information to find bounds on the sample itself. You may put in simple values for the information given if your prefer that to working directly with the formulas.

Suppose you were also given the P-value. Show how to obtain the test statistic from this, and the sample mean itself.

In another case –control study researchers investigated cleft lip with or without cleft palate by smoking status in those participants who reported consuming folic acid supplements. In this sub-group there were 42 cases of cleft lip with or without cleft palate and 55 controls who were current smokers; and there were 72 cases of cleft lip with or without cleft palate and 190 controls who were non-smokers.”

(a) “Construct a 2x2 table with columns and rows headings and calculate an appropriate measure of the strength of association between smoking and cleft lip with or without cleft palate in those who consumed folic acid supplements during pregnancy.” [4 marks]

b) “Interpret the findings in (a) in your own words.” [2 marks]

c) “What proportion of cleft lip with or without cleft palate in the population is potentially preventable, assuming a causal association between smoking and cleft lip.”[4 marks] explain in words your findings

Using the following sample data; 6, 7, 11, 6, 11, 5, 15, 11, 5;

Compute the sample standard deviation using either the computing formula or the defining formula.

Given are five observations for two variables,  and .

The estimated regression equation for these data is y = 70.84 - 2.83x

a. Compute SST, SSE , and SSR.

b. Compute the coefficient of determination r^2. Comment on the goodness of fit.

(to 3 decimals)

The least squares line provided an - Select your answer -goodbadItem 5 fit;   of the variability in  has been explained by the estimated regression equation (to 1 decimal).

c. Compute the sample correlation coefficient. Enter negative value as negative number.

(to 3 decimals)

El documento de Excel anexo presenta las estadísticas de criminalidad en una ciudad. También se presentan otros datos importantes a cerca de educación. El propósito de este ejercicio es crear dos modelos de regresión lineal múltiple donde se trate de predecir: a) Y1 usando como predictores X3,X5,X6 b) Y2 usando como predictores X3,X4,X7 En cada caso se necesita: 1. El modelo (todos los coeficientes beta) y la interpretación de cada coeficiente. 2. Cuan significativos son cada uno de los coeficientes 3. El coeficiente de determinación del modelo (R cuadrado) 4. La interpretación de R cuadrado 5. En el caso (a) prediga: Cuál será la tasa de crímenes totales reportados por milón de habitantes si se asignan 50 dólares anuales por habitante a la policía, hay un 10% de jóvenes entre 16 y 19 años que no asisten a la escuela superior (ni la han finalizado) y hay un 50% de jóvenes entre 18 y 24 años que asisten a la universidad. 6. En el caso (b) prediga: Cuántos crímenes de violencia se reportarán si se asignan 20 dólares anuales por habitante a la policía, hay 60% de personas de más de 25 años que finalizaron la escuela superior y hay un 5% de personas de 25 años o más que lograron una carrera universitaria de 4 años. 7. Luego de hacer todo este análisis arroje conclusiones prácticas acerca de los hallazgos hechos en esta ciudad. 8. Si usted es un consejero para las autoridades de esa ciudad, por favor escriba un parrafo de recomendaciones a seguir para tratar de reducir la criminalidad. ABAJO APARECEN CIERTAS FÓRMULAS QUE LE PUEDE SER DE UTILIDAD, AUNQUE LA RECOMENDACIÓN QUE RESUELVA TODO EL PROBLEMA USANDO R Y/O EXCEL PARA EL MISMO.

Describe in 175 words please type response:

Describe statistical inference and how it corralates with hypothesis testing for single populations.

Describe in 175 words please type response:

Describe how decision making is done using one sample hypothesis testing.

Suppose that you decide to randomly sample people ages 18-24 in your county to determine whether or not they are registered to vote. In your sample of 50 people, 35 said they were registered to vote. a) (2 points) Find a 95% confidence interval for the true proportion of the county population ages 18-24 who are registered to vote. Make sure to check any necessary conditions and to state a conclusion in the context of the problem. Also, explain what 95% confidence means in this context. b) (1 point) What is the probability that the true proportion of people ages 18-24 who registered to vote in your county is in your particular confidence interval? (Note: Be careful). c) (1 point) According to a separate news report, about 73% of 18- to 24-year-olds in the same county said that they were registered to vote. Does the 73% figure seem reasonable with your own poll? Explain. d) (1 point) Assume you have not done your poll yet, but you knew the news report poll results. In designing your poll now, you want separately estimate the same percentage to within ±4 percentage points with 95% confidence, how many people should you poll?

Consider a sample with data values of 26, 25, 20, 15, 31, 33, 29, and 25. Compute the 20th, 25th, 65th, and 75th percentiles.

20th percentile

25th percentile

65th percentile

75th percentile

4. One thousand cars were stopped at random for a roadside test of tyres and lights: 115 had unroadworthy tyres; and 46 had a lighting fault. These figures include 22 cars with both defects. If drivers had been fined $100 if their car had one defect, and $500 if their car had both defects, how much revenue would have been raised per car?

According to the latest financial reports from a sporting goods store, the mean sales per customer was $75 with a population standard deviation of $6. The store manager believes 39 randomly selected customers spent more per transaction.

What is the probability that the sample mean of sales per customer is between $76 and $77 dollars?

You may use a calculator or the portion of the z -table given below. Round your answer to two decimal places if necessary.

$\mu_{\overline{x}}=$ $

sigma sub line segment x is equal to $\sigma_{\overline{x}}=$

$

cap p times open paren 76 is less than or equal to line segment x comma line segment x is less than or equal to 77 close paren is equal to $P\left(76\le\overline{x}\le77\right)=$