Consider a paint-drying situation in which drying time for a test specimen is normally distributed with σ = 7. The hypotheses H0: μ = 74 and Ha: μ < 74 are to be tested using a random sample of n = 25 observations. (a) How many standard deviations (of X) below the null value is x = 72.3? (b) If x = 72.3, what is the conclusion using a = 0.01?

(a) The value = 72.3 is 1.21 standard deviations below the null value of μ.

(b) The mean drying time of paint is not less than 74.

Step-by-step explanation:

The hypothesis for the single mean test is:

H₀: μ = 74 vs. Hₐ: μ < 74.

The information provided is:

σ = 7

n = 25

As the population standard deviation is known, we will use a z-test for single mean.

(a)

The z-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 z-score for sample mean is given by:

If = 72.3 compute the corresponding z-score as follows:

Thus, the value = 72.3 is 1.21 standard deviations below the null value of μ.

(b)

So the test statistic is, z = -1.21.

Compute the p-value of the test as follows:

*Use a z-table.

The decision rule says to, reject the null hypothesis if the p-value is less than the significance level α = 0.01 and vice-versa.

p-value = 0.1131 < α = 0.01

The null hypothesis was failed to be rejected.

Thus, the mean drying time of paint is not less than 74.

step-by-step explanation:

a. turk and mcalister

b. howard, mission, and market

c. yes. since streets end some do not cross yet are not parallel to others. example: mcalister and 5th

step-by-step explanation:

parallel lines are lines which do not intersect ever and look a lot like railroad tracks. turk, mcalister and golden gate are examples of these.

intersect are streets which cross each other and a car on one can reach the other. howard, mission, and market intersect with 6th.

skew lines are lines which neither intersect nor are parallel. these lines exist here because some streets end and never intersect another like mcalister and 5th.