--%>
Assignment Help - homework help

What is your conclusion

The following data were collected on the number of emergency ambulance calls for an urban county and a rural county in Florida. Is County type independent of the day of the week in receiving the emergency ambulance calls? Use α = 0.005. What is your conclusion?

Day of the Week

Sun Mon Tue Wed Thu Fri Sat

County

Urban 62 47 48 51 61 74 41

Rural 6 10 18 17 11 13 12

E

Expert

Verified

Chi square test for independence is applied to test the independence of county from day of the weak.

 

Hypothesis Formation

H0: County is independent from day of the week.

H1: County is Not independent from day of the week.

Test Statistic

Χ2 = ∑(O – E)2/E

Expected Frequency table

Using the below formula, Expected frequencies for relevant columns and rows are calculated. 

Erc = nr*nc/n, where nr is total observed frequency in column c, nc is the total observed frequency in row r where n is total sample size.

 

       Sun        Mon        Tues       Wed       Thurs     Friday   Saturday

Urban  55.4       46.5       53.8       55.4       58.7       70.9       43.2   

Rural  12.6       10.5       12.2       12.6       13.3       16.1       9.79 

 

Critical value of χ2

d.f = (2-1)*(7-1)

      = 6

Upper Critical value χ2 with d.f=6 at significance level of 0.005 = 18.6

Lower Critical value χ2 with d.f=6 at significance level of 0.005 = 0.676

Critical Region

Reject null hypothesis if χ2 is greater than upper critical value of 18.6 or if less than lower critical value of 0.676.

Computation

χ2 = (62-55.4)2/55.4 + (47-46.5)2/46.5 + (48-53.8)2/53.8 + (51-55.4)2/55.4 + (61-58.7)2/58.7 + (74-70.9)2/70.9 + (41-43.2)2/43.2 + (6-12.6)2/12.6 + (10-10.5)2/10.5 + (18-12.2)2/12.2 + (17-12.6)2/12.6 + (11-13.3)2/13.3 + (13-16.1)2/16.1 + (12-9.79)2/9.79

= 11.4

Decision

As χ2 is neither less than 0.676 nor greater than 18.6, so we can’t reject null hypothesis. Therefore county is independent from day of the week.

 

   Related Questions in Basic Statistics

  • Q : Calculate the p- value Medical tests

    Medical tests were conducted to learn about drug-resistant tuberculosis. Of 284 cases tested in New Jersey, 18 were found to be drug- resistant. Of 536 cases tested in Texas, 10 were found to be drugresistant. Do these data indicate that New Jersey has a statisti

    		•
  • Q : Develop the most appropriate regression

    Predicting Courier Costs The law firm of Adams, Babcock, and Connors is located in the Dallas-Fort metroplex.  Randall Adams is the senior and founding partner of the firm.  John Babcock has been a partne

    		•
  • Q : Problem on queuing diagram Draw a 

    Draw a queuing diagram for the systems below and describe them using Kendall’s notation: A) Single CPU system <

    		•
  • Q : Regression Analysis 1. A planning

    1. A planning official in the Texas Department of Community Affairs, which works in the office next to you, has a problem. He has been handed a data set from his boss that includes the costs involved in developing local land use plans for communities wi

    		•
  • Q : Use the NW corner rule to find an

      (a) Use the NW corner rule to find an initial BFS, then solve using the transportation simplex method. Indicate your optimal objective function value. (b) Suppose we increase s1 from 15 to 16, and d3 from 10 to 11. S

    		•
  • Q : Building Models Building Models • What

    Building Models • What do we need to know to build a model?– For model checking we need to specify behavior • Consider a simple vending machine – A custome rinserts coins, selects a beverage and receives a can of soda &bul

    		•
  • Q : Statistics basic question This week you

    This week you will analyze if women drink more sodas than men.  For the purposes of this Question, assume that in the past there has been no difference.  However, you have seen lots of women drinking sodas the past few months.  You will perform a hypothesis test to determine if women now drink more

    		•
  • Q : Explain Queuing theory Queuing theory :

    Queuing theory: • Queuing theory deals with the analysis of lines where customers wait to receive a service:

    Q : Hw An experiment is conducted in which

    An experiment is conducted in which 60 participants each fill out a personality test, but not according to the way they see themselves. Instead, 20 are randomly assigned to fill it out according to the way they think a parent sees them (i.e. how a parent would fill it out to describe the participant

    		•
  • Q : Hypothesis homework A sample of 9 days

    A sample of 9 days over the past six months showed that a clinic treated the following numbers of patients: 24, 26, 21, 17, 16, 23, 27, 18, and 25. If the number of patients seen per day is normally distributed, would an analysis of these sample data provide evidence that the variance in the numbe

    		•