Answer:
an = 2⋅3n − 1
Step-by-step explanation:
a.
is a joint density function if its integral over the given support is 1:


so the answer is yes.
b. We should first find the density of the marginal distribution,
:


Then

or about 0.2019.
For the other probability, we can use the joint PDF directly:

which is about 0.7326.
c. We already know the PDF for
, so we just integrate:
![E[Y]=\displaystyle\int_{-\infty}^\infty y\,f_Y(y)\,\mathrm dy=\frac15\int_0^\infty ye^{-y/5}\,\mathrm dy=\boxed5](https://tex.z-dn.net/?f=E%5BY%5D%3D%5Cdisplaystyle%5Cint_%7B-%5Cinfty%7D%5E%5Cinfty%20y%5C%2Cf_Y%28y%29%5C%2C%5Cmathrm%20dy%3D%5Cfrac15%5Cint_0%5E%5Cinfty%20ye%5E%7B-y%2F5%7D%5C%2C%5Cmathrm%20dy%3D%5Cboxed5)
Answer: a) 0.8665
b) 0.8190
Step-by-step explanation:
Given : The partial pressure of oxygen PaO2 is a measure ofthe amount of oxygen in the blood. Assume that the distribution ofPaO2 levels among newborns has a
38 mmHg and
9 mmHg.
If we take a random sample n= 25 newborns, then using formula
, we have
At x= 36

At x= 41

Using table for z-values, the probability that the sample mean will be greater than 36 :

The probability that the sample mean will be between 36 and 41 :-

Answer:
Step-by-step explanation:
<u>We know that:</u>
- Samantha = 15 + 2x
- Matt = 3 + 4x
- Samantha = Matt
- [x = Number of hours]
<u>Solution:</u>
- 15 + 2x = 3 + 4x
- => 15 - 3 = -2x + 4x
- => 12 = 2x
- => x = 6
Hence, after 6 hours of work, Samantha and Matt will have the same amount.
Answer:24/67
Step-by-step explanation: