Data from the department of motor vehicles indicate that 80% of all licensed dri
ID: 3319933 • Letter: D
Question
Data from the department of motor vehicles indicate that 80% of all licensed drivers are older than age 25. In a sample of n = 60 people who recently received speeding tickets, 38 were older than 25 years and the other 22 were age 25 or younger. Is the age distribution for this sample significantly different from the distribution for the population of licensed drivers? Use = .05.
The null hypothesis? The alternative hypothesis?
What are the degrees of freedom?
What is the critical value?
The OBSERVED frequency of drivers over 25 is
The EXPECTED frequency of drivers over 25 is
The OBSERVED frequency of drivers 25 or younger is
The EXPECTED frequency of drivers 25 or younger is
What is the obtained Chi Square test statistic?
What is the correct decision?
I. Accept Ho II. Reject Ho III. Accept H1 IV. Reject H1
Explanation / Answer
observed frequncies are Oi
38 22
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expected frequencies are Ei
80%of 60 = 48, 20% of 60 = 12
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and claiming hypothesis is
null, Ho: no association exists b/w them
alternative, H1: sample significantly different from the distribution for the population of licensed drivers
level of significance, = 0.05
from standard normal table, chi square value at right tailed, ^2 /2 =5.9915
since our test is right tailed,reject Ho when ^2 o > 5.9915
we use test statistic ^2 o = (Oi-Ei)^2/Ei
from the table take sum of (Oi-Ei)^2/Ei, we get ^2 o = 10.4166
critical value
the value of |^2 | at los 0.05 with d.f, n - 1 = 3 - 1 = 2 is 5.9915
we got | ^2| =10.4166 & | ^2 | =5.9915
make decision
hence value of | ^2 o | > | ^2 | and here we reject Ho
^2 p_value =0.0055
ANSWERS
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null, Ho: no association exists b/w them
alternative, H1: sample significantly different from the distribution for the population of licensed drivers
test statistic: 10.4166
critical value: 5.9915
p-value:0.0055
decision: reject Ho
Observed (Oi ) Expected ( Ei) Oi-Ei (Oi-Ei)^2 (Oi-Ei)^2/Ei 38 48 -10 100 2.0833 22 12 10 100 8.3333Related Questions
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