Answer
$P(three~strikes~in~a~row~then~not~strike)=0.0189$
Work Step by Step
$30$% $=0.3$
$P(strike)=0.3$
The event "not strike" is the complement of "strike". So, we use the Complement Rule (see page 275):
$P(not~strike)=1-P(strike)=1-0.3=0.7$
Using the Multiplication Rule (see page 282):
$P(three~strikes~in~a~row~then~not~strike)=P(strike~1)\times P(strike~2)\times P(strike~3)\times P(not~strike~4)=0.3\times0.3\times0.3\times0.7=0.0189$
