Answer:
She needs to do at least 8 a day
Step-by-step explanation:
Answer:

Step-by-step explanation:

Apply absolute rule: 

Multiply:


______________________
Answer:
8 cm
Step-by-step explanation:
(See the image attached for details)
- The blue segment measures 15 cm
- The green segment measures 7 cm
- The green and yellow segment when added form the blue segment
- So: ? + 7 = 15
Solve:
? + 7 = 15
Subtract 7 on both sides:
? + 7 = 15
-7 -7
? = 8 cm
Therefore, the yellow segment, or the missing side length, measures 8 cm.
Answer:
a. CI=[128.79,146.41]
b. CI=[122.81,152.39]
c. As the confidence level increases, the interval becomes wider.
Step-by-step explanation:
a. -Given the sample mean is 137.6 and the standard deviation is 20.60.
-The confidence intervals can be constructed using the formula;

where:
is the sample standard deviation
is the s value of the desired confidence interval
we then calculate our confidence interval as:
![\bar X\pm z\frac{s}{\sqrt{n}}\\\\=137.60\pm z_{0.05/2}\times\frac{20.60}{\sqrt{21}}\\\\=137.60\pm1.960\times \frac{20.60}{\sqrt{21}}\\\\=137.60\pm8.8108\\\\\\=[128.789,146.411]](https://tex.z-dn.net/?f=%5Cbar%20X%5Cpm%20z%5Cfrac%7Bs%7D%7B%5Csqrt%7Bn%7D%7D%5C%5C%5C%5C%3D137.60%5Cpm%20z_%7B0.05%2F2%7D%5Ctimes%5Cfrac%7B20.60%7D%7B%5Csqrt%7B21%7D%7D%5C%5C%5C%5C%3D137.60%5Cpm1.960%5Ctimes%20%5Cfrac%7B20.60%7D%7B%5Csqrt%7B21%7D%7D%5C%5C%5C%5C%3D137.60%5Cpm8.8108%5C%5C%5C%5C%5C%5C%3D%5B128.789%2C146.411%5D)
Hence, the 95% confidence interval is between 128.79 and 146.41
b. -Given the sample mean is 137.6 and the standard deviation is 20.60.
-The confidence intervals can be constructed using the formula in a above;
![\bar X\pm z\frac{s}{\sqrt{n}}\\\\=137.60\pm z_{0.01/2}\times\frac{20.60}{\sqrt{21}}\\\\=137.60\pm3.291\times \frac{20.60}{\sqrt{21}}\\\\=137.60\pm 14.7940\\\\\\=[122.806,152.394]](https://tex.z-dn.net/?f=%5Cbar%20X%5Cpm%20z%5Cfrac%7Bs%7D%7B%5Csqrt%7Bn%7D%7D%5C%5C%5C%5C%3D137.60%5Cpm%20z_%7B0.01%2F2%7D%5Ctimes%5Cfrac%7B20.60%7D%7B%5Csqrt%7B21%7D%7D%5C%5C%5C%5C%3D137.60%5Cpm3.291%5Ctimes%20%5Cfrac%7B20.60%7D%7B%5Csqrt%7B21%7D%7D%5C%5C%5C%5C%3D137.60%5Cpm%2014.7940%5C%5C%5C%5C%5C%5C%3D%5B122.806%2C152.394%5D)
Hence, the variable's 99% confidence interval is between 122.81 and 152.39
c. -Increasing the confidence has an increasing effect on the margin of error.
-Since, the sample size is particularly small, a wider confidence interval is necessary to increase the margin of error.
-The 99% Confidence interval is the most appropriate to use in such a case.
4 because you can take it out of both of them ( ps I'm really bad at math but I'm pretty sure I'm right)