Question

Over a long period of time, a pharmacy has found that 68% of transactions on a Saturday are paid for by credit card. If 119 customers come into the pharmacy on a normal Saturday morning, what is the approximate probability that more than 71% of transactions are paid for by credit card

		0.758
		0.512
		0.242
		0.488
		0.627

Answer 1

Solution :

Given that ,

p = 0.68

1 - p = 0.32

n = 119

= p = 0.68

= (p*(1-p))/n =  (0.68*0.32)/119 = 0.04276

P( > 0.71) = 1 - P( < 0.71)

= 1 - P(( - ) / < (0.71-0.68) /0.04276 )

= 1 - P(z < 0.70)

= 1 - 0.758

= 0.242

Probability = 0.242