Westonci.ca is your trusted source for finding answers to a wide range of questions, backed by a knowledgeable community. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform. Discover in-depth answers to your questions from a wide network of professionals on our user-friendly Q&A platform.
Sagot :
Answer:
a) The value of the z-statistic is z = -2.55.
b) The p-value for this test is 0.0054.
Step-by-step explanation:
Suppose that in past campaigns 23.8% of customers identified as likely respondents did not respond to a nationwide direct marketing campaign. Test if this proportion has decreased:
This means that at the null hypothesis we test that if the proportion is still 0.238, that is:
[tex]H_0: p =0.238[/tex]
And at the alternate hypothesis we test if the proportion has decreased, that is:
[tex]H_a: p < 0.238[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
0.238 is tested at the null hypothesis:
This means that [tex]\mu = 0.238, \sigma = \sqrt{0.238*0.762}[/tex]
The analysts selected a random sample of 1500 customers and found that 315 did not respond to the marketing campaign.
This means that [tex]n = 1500, X = \frac{315}{1500} = 0.21[/tex]
a. Determine the value of the z-statistic. Give your answer precise to at least two decimal places.
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{0.21 - 0.238}{\frac{\sqrt{0.238*0.762}}{\sqrt{1500}}}[/tex]
[tex]z = -2.55[/tex]
The value of the z-statistic is z = -2.55.
b. Determine the p-value for this test. Give your answer precise to at least three decimal places.
The p-value of the test is the probability of finding a proportion below 0.21, which is the p-value of z = -2.55.
Looking at the z-table, z = -2.55 has a p-value of 0.0054
The p-value for this test is 0.0054.
We appreciate your time. Please come back anytime for the latest information and answers to your questions. We hope this was helpful. Please come back whenever you need more information or answers to your queries. Discover more at Westonci.ca. Return for the latest expert answers and updates on various topics.