Question

Suppose someone claims they can make it in and out of the grocery store in less than 10 minutes. Let's take a sample of 15 shoppers with a mean of 9.8 minutes and a standard deviation of 0.4 minutes. Can the claim at an alpha of 0.05?

Answer #1

Solution :

Given that,

= 10

= 9.8

= 0.4

n = 15

The null and alternative hypothesis is ,

H0 : = 10

Ha : < 10

This is the left tailed test .

Test statistic = z

= ( - ) / / n

= ( 9.8 - 10 ) / 0.4 / 15

= -1.94

Test statistic = -1.94

P (Z < -1.94 ) = 0.0262

P-value = 0.0262

= 0.05

0.0262 < 0.05

P-value < .

Reject the null hypothesis .

**There is sufficient evidence to claim the test at an
alpha of 0.05**

A local hardware store claims that the mean waiting time in line
is less than 3.7 minutes. A random sample of 20 customers has a
mean of 3.5 minutes with a standard deviation of 0.8 minute. If α =
0.05, test the bank's claim.
Null:
Alternative:
T=
p-Value=
Choose one: Reject or Fail to Reject
Conclusion in Context:

A call center claims their average call lasts 6 minutes. Let's
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The owner of a local grocery chain claims that the true mean
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0.5
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