Answer:
![x^{2} \geq 186\neq](https://tex.z-dn.net/?f=x%5E%7B2%7D%20%5Cgeq%20186%5Cneq)
Step-by-step explanation:
Answer:
X=0.2
Step-by-step explanation:
0.17x+1.2=1.234
0.17x=1.234-1.2
0.17x=0.034
17x=3.4
x=3.4/17
x=0.2
First find how many were deleted, by subtracting the remaining amount from the original amount:
215 - 129 = 86 pictures deleted.
Now divide the amount deleted by the original amount:
86 / 215 = 0.4
Multiply by 100:
0.4 x 100 = 40%
There was a 40% decrease.
<span>0.1428571428 would be the correct answer</span>
Using the z-distribution, the estimate for how much the drug will lower a typical patient's systolic blood pressure is:
![46.6 \leq \mu \leq 48](https://tex.z-dn.net/?f=46.6%20%5Cleq%20%5Cmu%20%5Cleq%2048)
<h3>What is a z-distribution confidence interval?</h3>
The confidence interval is:
![\overline{x} \pm z\frac{\sigma}{\sqrt{n}}](https://tex.z-dn.net/?f=%5Coverline%7Bx%7D%20%5Cpm%20z%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D)
In which:
is the sample mean.
is the standard deviation for the population.
In this problem, we have a 80% confidence level, hence
, z is the value of Z that has a p-value of
, so the critical value is z = 1.28.
The other parameters are given by:
![\overline{x} = 47.3, \sigma = 15.9, n = 878](https://tex.z-dn.net/?f=%5Coverline%7Bx%7D%20%3D%2047.3%2C%20%5Csigma%20%3D%2015.9%2C%20n%20%3D%20878)
Then the bounds of the interval are:
![\overline{x} - z\frac{\sigma}{\sqrt{n}} = 47.3 - 1.28\frac{15.9}{\sqrt{878}} = 46.6](https://tex.z-dn.net/?f=%5Coverline%7Bx%7D%20-%20z%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D%20%3D%2047.3%20-%201.28%5Cfrac%7B15.9%7D%7B%5Csqrt%7B878%7D%7D%20%3D%2046.6)
![\overline{x} + z\frac{\sigma}{\sqrt{n}} = 47.3 + 1.28\frac{15.9}{\sqrt{878}} = 48](https://tex.z-dn.net/?f=%5Coverline%7Bx%7D%20%2B%20z%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D%20%3D%2047.3%20%2B%201.28%5Cfrac%7B15.9%7D%7B%5Csqrt%7B878%7D%7D%20%3D%2048)
Hence the interval is:
![46.6 \leq \mu \leq 48](https://tex.z-dn.net/?f=46.6%20%5Cleq%20%5Cmu%20%5Cleq%2048)
More can be learned about the z-distribution at brainly.com/question/25890103
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