<span>Distance is equal to rate times time, and time is the unknown in this instance. To find time, divide distance by rate. In this case, Joe wants to use a rate five miles per hour less than his planned speed of 75 miles per hour, which is 70. Dividing 310 miles by 70 miles per hour yields an expected travel time of 4.4 hours.</span>
Answer:
Ball Bearing Volume = (4 / 3) * PI * radius ^3
Volume = (4 / 3) * 3.14159265 * (.35)^3
Volume = (4 / 3) * 3.14159265 * 0.042875
Volume = 0.17959438 cc
1 cc of steel = 7.8 g
Volume of 1 kg of steel = 1,000 cc / 7.8 g per cc
1 kg = 128.205 cc
Number of ball bearings we can make = 128.205 / 0.17959438
Equals 713.86
Step-by-step explanation:
Answer:
The value of the test statistic is z = -0.877.
Step-by-step explanation:
Testing the difference in mean time spent on housework between husbands and wives.
At the null hypothesis, we test if there is no difference, that is, the subtraction of the means is 0:
![H_0: \mu_H - \mu_W = 0](https://tex.z-dn.net/?f=H_0%3A%20%5Cmu_H%20-%20%5Cmu_W%20%3D%200)
At the alternate hypothesis, we test if there is a difference, that is, the subtraction of the means is different from 0.
![H_1: \mu_H - \mu_W \neq 0](https://tex.z-dn.net/?f=H_1%3A%20%5Cmu_H%20-%20%5Cmu_W%20%5Cneq%200)
The test statistic is:
![z = \frac{X - \mu}{s}](https://tex.z-dn.net/?f=z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7Bs%7D)
In which X is the sample mean,
is the value tested at the null hypothesis, and s is the standard error.
0 is tested at the null hypothesis:
This means that ![\mu = 0](https://tex.z-dn.net/?f=%5Cmu%20%3D%200)
For the wives the mean was 7 hours/week and for the husbands the mean was 4.5 hours/week. The standard deviation of the differences in time spent on house work was 2.85.
This means that ![X = 4.5 - 7 = -2.5, s = 2.85](https://tex.z-dn.net/?f=X%20%3D%204.5%20-%207%20%3D%20-2.5%2C%20s%20%3D%202.85)
What is the value of the test statistic for testing the difference in mean time spent on housework between husbands and wives?
![z = \frac{X - \mu}{s}](https://tex.z-dn.net/?f=z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7Bs%7D)
![z = \frac{-2.5 - 0}{2.85}](https://tex.z-dn.net/?f=z%20%3D%20%5Cfrac%7B-2.5%20-%200%7D%7B2.85%7D)
![z = -0.877](https://tex.z-dn.net/?f=z%20%3D%20-0.877)
The value of the test statistic is z = -0.877.
Answer:
-4m-3
Step-by-step explanation: