Suppose A is a positive real number and mA is the average value of (sin(Ax))3 on the
1 answer:
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Answer:
a: 0.9544 9 within 8 units)
b: 0.9940
Step-by-step explanation:
We have µ = 300 and σ = 40. The sample size, n = 100.
For the sample to be within 8 units of the population mean, we would have sample values of 292 and 308, so we want to find:
P(292 < x < 308).
We need to find the z-scores that correspond to these values using the given data. See attached photo 1 for the calculation of these scores.
We have P(292 < x < 308) = 0.9544
Next we want the probability of the sample mean to be within 11 units of the population mean, so we want the values from 289 to 311. We want to find
P(289 < x < 311)
We need to find the z-scores that correspond to these values. See photo 2 for the calculation of these scores.
We have P(289 < x < 311) = 0.9940
Answer:
Explained below.
Step-by-step explanation:
(1)
The hypothesis can be defined as follows:
<em>H</em>₀: The Speedy Oil Change will change the oil in customers’ cars in more than 30 minutes on average, i.e. <em>μ</em> > 30.
<em>H</em>ₐ: The Speedy Oil Change will change the oil in customers’ cars in less than 30 minutes on average, i.e. <em>μ</em> ≤ 30.
(2)
Use Excel to compute the sample mean and standard deviation as follows:
Compute the test statistic as follows:
The degrees of freedom is:
df = n - 1
= 36 - 1
= 35
Compute the p-value as follows:
(3)
The <em>p</em>-value = 0.0006 is very small.
The null hypothesis will be rejected at any of the commonly used significance level.
(4)
There is sufficient evidence to support the claim that the Speedy Oil Change will change the oil in customers’ cars in less than 30 minutes on average.
