Answer:
The probability that seven or more of them used their phones for guidance on purchasing decisions is 0.7886.
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Step-by-step explanation:
<em>The question is incomplete:</em>
<em>What should I buy? A study conducted by a research group in a recent year reported that 57% of cell phone owners used their phones inside a store for guidance on purchasing decisions. A sample of 14 cell phone owners is studied. Round the answers to at least four decimal places. What is the probability that seven or more of them used their phones for guidance on purchasing decisions? </em>
We can model this as a binomial random variable, with p=0.57 and n=14.
a) We have to calculate the probability that seven or more of them used their phones for guidance on purchasing decisions:
Answer:
![$\[x^2 + 22x + 121\]$](https://tex.z-dn.net/?f=%24%5C%5Bx%5E2%20%2B%2022x%20%2B%20121%5C%5D%24)
Step-by-step explanation:
Given
![$\[x^2 + 22x + \underline{~~~~}.\]$](https://tex.z-dn.net/?f=%24%5C%5Bx%5E2%20%2B%2022x%20%2B%20%5Cunderline%7B~~~~%7D.%5C%5D%24)
Required
Fill in the gap
Represent the blank with k
![$\[x^2 + 22x + k\]$](https://tex.z-dn.net/?f=%24%5C%5Bx%5E2%20%2B%2022x%20%2B%20k%5C%5D%24)
Solving for k...
To do this, we start by getting the coefficient of x
Coefficient of x = 22
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Divide the coefficient by 2
Take the square of this result, to give k
Substitute 121 for k
The expression can be factorized as follows;
<em>Hence, the quadratic expression is </em><em></em>
Answer:
D
Step-by-step explanation:
Answer:
14
Step-by-step explanation:
Well, first you'd have to get the x by it's self.
10x+1=3x+9
Subtract 3x from each side and you'll have the x on only one side rather than two.
7x+1=9
Now I'd get rid of the 1 on the x's side. So just subtract 1 from each side.
7x=8
Then you should make it so the seven isn't there with the x either. Just divide each side by 7.
Answer: x=8/7
Each time you change something on one side, you must do the same to the other side. T find the value of a variable in an equation, simple seclude it so it's on it's own without number to make things confusing.
The answer was x=8/7 btw.
