--%>
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 : OIL I need to product when oil will

    I need to product when oil will finish time (by years) for 6 countries if the keep their production (per day) in the same level. So, the 6 countries have fixed reserves and production 1. statistics for Bahrain Crude oil reserves (million barrels) = 124.6 be careful in million Crude oil producti

    		•
  • Q : Networks of queues Networks of queues •

    Networks of queues • Typically, the flow of customers/request through a system may involve a number of different processing nodes.– IP packets through a computer network– Orders through a manufactur

    		•
  • Q : Correlation analysis and the regression

    1).  When you take out a mortgage, there are many different kinds of costs.  Usually the two largest are the interest rate (annual percentage that determines the size of your monthly payment) and the loan fee (a one-time percentage charged to you at the time

    		•
  • 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 : Computing Average revenue using

    Can anyone help me in the illustrated problem? The airport branch of a car rental company maintains a fleet of 50 SUVs. The inter-arrival time between the requests for an SUV is 2.4 hrs, on an average, with a standard deviation of 2.4 hrs. There is no indication of a

    		•
  • Q : Principles of data analysis For the

    For the data analysis project, you will address some questions that interest you with the statistical methodology we are learning in class. You choose the questions; you decide how to collect data; you do the analyses. The questions can address almost any topic,

    		•
  • Q : Data Description 1. If the mean number

    1. If the mean number of hours of television watched by teenagers per week is 12 with a standard deviation of 2 hours, what proportion of teenagers watch 16 to 18 hours of TV a week? (Assume a normal distribution.) A. 2.1% B. 4.5% C. 0.3% D. 4.2% 2. The probability of an offender having a s

    		•
  • Q : Assumptions in Queuing system

    Assumptions in Queuing system: • Flow balance implies that the number of arrivals in an observation period is equal to the

    		•
  • Q : Average think time Software monitor

    Software monitor data for an interactive system shows a CPU utilization of 75%, a 3 second CPU service demand, a response time of 15 seconds, and 10 active users. Determine the average think time of these users?

    		•
  • 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

    		•