Question

The claim is that the proportion of adults who smoked a cigarette in the past week is less than 0.25​, and the sample statistics include n=1906 subjects with 457 saying that they smoked a cigarette in the past week. Find the value of the test statistic.

Answer 1

Result:

The claim is that the proportion of adults who smoked a cigarette in the past week is less than 0.25​, and the sample statistics include n=1906 subjects with 457 saying that they smoked a cigarette in the past week. Find the value of the test statistic.

One sample proportion test

Ho: P=0.25, H1: P< 0.25

p=457/1906 = 0.2398

= -1.0315

Test statistic z = -1.0315

Table value of z at 0.05 level = -1.645

Rejection Region: Reject Ho if z < -1.645

Calculated z = -1.0315 , not in the rejection region

The null hypothesis is not rejected.

There is not enough evidence to support the claim.

Z Test of Hypothesis for the Proportion
Data
Null Hypothesis            p =	0.25
Level of Significance	0.05
Number of Items of Interest	457
Sample Size	1906
Intermediate Calculations
Sample Proportion	0.23976915
Standard Error	0.0099
Z Test Statistic	-1.0315
Lower-Tail Test
Lower Critical Value	-1.645
p-Value	0.1512
Do not reject the null hypothesis