--%>

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 : Problem on Model Checking Part (a).

    Part (a). Draw a state diagram for a car with the following state variables: D indicating whether the car is in drive; B indicating the brake pedal is depressed; G indicating the gas pedal is depressed; and M indicating whether the car is moving. (For example, the sta

  • Q : Designing a system What are the

    What are the questions that comes into mind when designing a system?

  • Q : FIN512 Entrepreneurial Finance Chapter

      Chapter 6: Discussion Question: #4 p. 223  It is usually easier to forecast sales for a seasoned firm contrast to an early-stage venture because an early-stage venture has limited access to bank credit lines, sho

  • Q : Help An experiment is conducted in

    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 : 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 : Statistics for Management Assignment

    Q : Safety and Liveness in Model Checking

    Safety and Liveness in Model Checking Approach; •? Safety: Nothing bad happens •? Liveness: Something good happens •? Model checking is especially good at verifying safety and liveness properties    –?Concurrency i

  • 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 : 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 : Statics for each of the following

    for each of the following studies a and b decide whether to reject the null hypothesis that groiups come from identical populations. Use the .01 level. (c) Figure the effects size for each study. (d) ADVANCED TOPIC: Carry out an analysis of variance for study (a) using the strucurtal method.