Ben has a collection of 812 stamps. He gives his brother 345 stamps. About how many stamps Ben have left?
2 answers:
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Answer:
(a) The value = 72.3 is 1.21 standard deviations below the null value of <em>μ</em>.
(b) The mean drying time of paint is not less than 74.
Step-by-step explanation:
The hypothesis for the single mean test is:
<em>H₀</em>: <em>μ</em> = 74 vs. <em>Hₐ</em>: μ < 74.
The information provided is:
<em>σ</em> = 7
<em>n</em> = 25
As the population standard deviation is known, we will use a <em>z</em>-test for single mean.
(a)
The <em>z</em>-score is a Normal distribution with mean 0 and variance 1. It is also defined as the number of standard deviations a raw score is from the mean.
The <em>z</em>-score for sample mean is given by:
If = 72.3 compute the corresponding <em>z</em>-score as follows:
Thus, the value = 72.3 is 1.21 standard deviations below the null value of <em>μ</em>.
(b)
So the test statistic is, <em>z</em> = -1.21.
Compute the <em>p</em>-value of the test as follows:
*Use a <em>z</em>-table.
The decision rule says to, reject the null hypothesis if the <em>p</em>-value is less than the significance level <em>α</em> = 0.01 and vice-versa.
<em>p</em>-value = 0.1131 < <em>α</em> = 0.01
The null hypothesis was failed to be rejected.
Thus, the mean drying time of paint is not less than 74.
Answer:
Step-by-step explanation:
1. You have the following information given in the problem:
- The distance to the nearest exit door is no more than 150 feet.
- represents the distance to the nearest exit door, in feet.
2. Therefore, keeping the information above on mind, you know that the distance to the nearest exit door () must be less than or equal to 150 feet, then, you can express this as following: