Hi! looking for some help with the solution to this exercise. Thanks! Textbook:

Question

Hi! looking for some help with the solution to this exercise. Thanks!

Textbook: An Introduction to Statistical Methods and Data Analysis, 6th Edition, Ott & Longnecker

Ch.10 Problem 31E (10.31)

Does weather affect the occurrence of violent crimes? Sociologists have long debated whether certain atmospheric conditions are associated with increases in the homicide rate. A       researcher classified 1,500 homicides in the southwest region of the United States according    to the seasons in which the homicide occurred.

Winter Spring Summer Fall Total
Number of Homicides 328 372 471 329 1,500
% of Total 21.87 24.80 31.40 21.93 100

a. Do the data support the contention that the homicide rates are different for the four
seasons? Use alpha= .05.
b. Does your conclusion from (a) lend evidence to support the sociologists’ contention
that weather affects homicide rate?

Explanation / Answer

Ans:

Ans:

H0:homicide rate are same for four season(independent)

H1:homicider rates are different for four seaons(not independent)

O=observed

E=Expected

Expected count=1500/4=375

Calculated Chi square=36.133

Critical chi square (for significance level of 0.05 and df=4-1=3 )= 7.815

p-value=0

As,calculated Chi square>critical chi square,We reject null hypothesis.

There is sufficient evidence to support the contention that homicides rates are different for four seasons.

Yes,we have evidence that weather affects the homicides rates i.e. both are not indpendent.

winter spring summer fall Total Number of homicides(O) 328 372 471 329 1500 Number of homicides(E) 375 375 375 375 1500 (O-E)^2/E 5.891 0.024 24.576 5.643 36.133

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.