Answer: The original price of brownie was $2.1 each.
Step-by-step explanation:
since we have given that
Let the original price will be x
Number of brownie purchased = 8
According to question , each brownie costs $0.20 less than the original price.
So, it becomes
Hence, the original price of brownie was $2.1 each.
The confidence interval comes out to be (0.685,0.735).
Calculating the Confidence Level and Other Terms
The confidence level can be calculated as follows,
z = %
z = 90 %
The margin error is given as, E= 0.025
The p value in this case is 0.71
Calculating the Confidence Interval
The mean of your estimate plus and minus the range of that estimate constitutes a confidence interval. Within a specific level of confidence, this is the range of values you anticipate your estimate to fall within if you repeat the test.
Confidence interval can be obtained by using the following formula,
(p-E, p+E) = (0.71-0.025, 0.71+0.025).
Therefore, the confidence interval is (0.685, 0.735).
Learn more about confidence interval here:
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