The price of a cup of coffee was $2.35 yesterday. Today, the price fell to $2.10. Find the percentage decrease. Round your answe
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Answer:
we will fail to reject the null hypothesis and conclude that the mean pressure is not different from 4.7 psi
Step-by-step explanation:
Let's first define the hypothesis;
Null hypothesis: H0: μ = 4.7
Alternative hypothesis: Ha: μ ≠ 4.7
We have;
Sample size; n = 110
Sample mean; x¯ = 4.6
Variance: σ² = 0.64
Standard deviation; σ = √0.64 = 0.8
Formula for test statistic is;
z = (x¯ - μ)/(σ/√n)
z = (4.6 - 4.7)/(0.8/√110)
z = -0.1/0.0763
z = -1.31
From online p-value from z-score calculator attached, using; z = -1.31, two tailed hypothesis, significance value of 0.1, we have;
P-value = 0.190196
The p-value is greater than the significance value and thus we will fail to reject the null hypothesis and conclude that the mean pressure is not different from 4.7
σ μ
