Answer:
The answer is B
Step-by-step explanation:
Your welcome
Answer:
The sample size is
Step-by-step explanation:
From the question we are told that
The margin of error is 
The standard deviation is 
From the question we are told the confidence level is 94% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of
is
Generally the sample size is mathematically represented as
=>
=>
27.7-14=Cost above 500 msg
13.7=C
E=number of Extra messages sent
C=0.1E
13.7/0.1=E
137=E
Total messages=T
T=500+E
T=500+137
T=637
Danielle sent 637 messages in September