Answer:
![a)\ \ \bar x_m-\bar x_f=67.03\\\\b)\ \ E=15.7416\\\\c)\ \ CI=[51.2884, \ 82.7716]](https://tex.z-dn.net/?f=a%29%5C%20%5C%20%5Cbar%20x_m-%5Cbar%20x_f%3D67.03%5C%5C%5C%5Cb%29%5C%20%5C%20E%3D15.7416%5C%5C%5C%5Cc%29%5C%20%5C%20CI%3D%5B51.2884%2C%20%5C%2082.7716%5D)
Step-by-step explanation:
a. -Given that:

#The point estimator of the difference between the population mean expenditure for males and the population mean expenditure for females is calculated as:

Hence, the pointer is estimator 67.03
b. The standard error of the point estimator,
is calculated by the following following:

-And the margin of error, E at a 99% confidence can be calculated as:

Hence, the margin of error is 15.7416
c. The estimator confidence interval is calculated using the following formula:

#We substitute to solve for the confidence interval using the standard deviation and sample size values in a above:
![CI=\bar x_m-\bar x_f\ \pm z_{\alpha/2}\sqrt{\frac{\sigma_m^2}{n_m}+\frac{\sigma_f^2}{n_f}}\\\\=(135.67-68.64)\pm 15.7416\\\\=67.03\pm 15.7416\\\\=[51.2884, \ 82.7716]](https://tex.z-dn.net/?f=CI%3D%5Cbar%20x_m-%5Cbar%20x_f%5C%20%5Cpm%20z_%7B%5Calpha%2F2%7D%5Csqrt%7B%5Cfrac%7B%5Csigma_m%5E2%7D%7Bn_m%7D%2B%5Cfrac%7B%5Csigma_f%5E2%7D%7Bn_f%7D%7D%5C%5C%5C%5C%3D%28135.67-68.64%29%5Cpm%2015.7416%5C%5C%5C%5C%3D67.03%5Cpm%2015.7416%5C%5C%5C%5C%3D%5B51.2884%2C%20%5C%2082.7716%5D)
Hence, the 99% confidence interval is [51.2884,82.7716]
Answer:
Step-by-step explanation:
HERE ARE THE ANSWERS
<span>A word problem that can be modeled by addition of two negative numbers integers is given as followed.
Evans and Irvin are standing at the same spot. Evans took 7 steps backwards and another 7 steps backward, what is the current position of Evans relative to where Irvin is standing?
To solve the above, we note that Evans </span><span>took 7 steps backwards and another 7 steps backward, thus his current position relative to Irvin is given by (-7) + (-7) = -7 - 7 = -14.
Therefore, Evans is 14 steps backwards relative to where Irvin is standing.
</span>
The domain of the function is the set of all x's that are suitable for the given equation. In the problem, we are asked to determine the equation with the most restricted domain. Option A can have x from negative infinity to positive infinity as well as option B and option D. OPtion C can only have x equal to zero and all positive numbers. Hence the answer is C. hope that helped