How to use bionominal distribution to solve extended response questions?

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Can someone please help me with question 16? Thanks!

1 Answer
Feb 26, 2018

#0.01386# (4sf)

Explanation:

Let #X# be the number of questions that you answer correctly.

We begin like this so we have defined our variable for the rest of the question

Let #X~B(20, 1/4)#

X is binomially distributed about 20 trials, probability of success is 1/4

#P(X>=10)=1-P(X<=9)#

You can find #P(X<=9)# using your calculator

#P(X>=10)=1-0.9861#

#=0.01386# (4sf)