To avoid unpleasant surprises when the statement comes, you try to record all your credit card transactions in a ledger. Unfortunately, you tend to neglect recording about 5% of your purchases. Suppose that last month, you had 25 purchases on your credit card account. When the statement arrives, you count the number of purchases you forgot to record. The random variable X represents the number of unrecorded transactions in a month with 25 transactions. Explain why this is a binomial experiment. Find and interpret the mean of X. Compute the standard deviation of X. Find the probability that you record all 25 purchases. Find the probability that exactly four purchases would have been unrecorded.

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Step-by-step explanation:

Just don't answer this question . Nobody can do anything about it . The teacher can't just go through the screen so . . . . just don't answer it . Wrong or right so nothing can really happen

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12

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step-by-step explanation: