Answer: 27.44 % decrease in gas prices
Step-by-step explanation: First subtract 2.15 by 1.56 to get 0.59
then divide it by the starting value which is 2.15
0.59 divided by 2.15 is approximately 0.2744
then multiply times 100 to get 27.44 %
hope this helps mark me brainliest if it helped
Answer: Analysis of variance
Step-by-step explanation:
Analysis of variance is the statistical test that's used in analyzing the differences among means. The analysis of variance is used to determine if a statistically significant differences exust between the means of the independent groups.
Based on the question given, the null hypothesis will be that no difference in the importance that's attached to shopping by the consumers living in different regions in the United States.
Answer:



Step-by-step explanation:
Given

Solving (a): Point estimate of difference of mean
This is calculated as: 


Solving (b): 90% confidence interval
We have:


Confidence level is: 



Calculate 


The z score is:

The endpoints of the confidence level is:






Split


Hence, the 90% confidence interval is:

Solving (c): 95% confidence interval
We have:


Confidence level is: 



Calculate 


The z score is:

The endpoints of the confidence level is:






Split


Hence, the 95% confidence interval is:
