Given
p = 0.84
n = 7
x = 6 or more successes
The probability is given by:
[tex]P=C_n^x\cdot p^x\cdot(1-p)^{n-x}[/tex]Then, substitute the values:
[tex]P=(\frac{7\cdot6\cdot5\cdot4\cdot3\cdot2}{1\cdot2\cdot3\cdot4\cdot5\cdot6})\cdot0.84^6\cdot(1-0.84)^{7-6}[/tex]Simplify:
[tex]P=(7)\cdot0.84^6\cdot0.16^1=0.3934[/tex]Round three decimal places is 0.393.
Answer: the probability is 0.393