It was reported that 23% of U. S. adult cellphone owners called a friend for advice about a purchase while in a store. If a sample of 15 U. S adult cellphone owners is selected, what is the probability that 7 called a friend for advice about a purchase while in a store

And using the probability mass function we got:

Step-by-step explanation:

Let X the random variable of interest, on this case we now that:  

The probability mass function for the Binomial distribution is given as:  

Where (nCx) means combinatory and it's given by this formula:  

And we want to find the following probability:

And using the probability mass function we got:

-14

step-by-step explanation:

2x2 – 2(x+4)

=2x2-2（5+4）

=4-2×9

=4-18

=-14

x = 17

step-by-step explanation:

in the given figure, two triangles are inscribed in a circle where ∠bae ≅ ∠dae which makes the side be and de equal so we can write it as:

3x - 24 = x + 10

solving this equation for x to get:

3x - x = 10 + 24

2x = 34

x = 34/2

x = 17

therefore, the value of x = 17.