Over the past few years, banks have strongly promoted online banking and the paying of bills online.stat

Question

In 2003, about 50% of internet usr paid bills online.  In a recent survey of 250 internet users, 150 said that they pay bills online.  At the 5% level of significance, test whether the proportion of internet users paying  bills online is now more than 50%.

Answer 1

Here the population proportion is .5 and the survey sample proportion is 150/250=.6. To find our standard deviation, we find the square root of (p*(1-p) or .5 in this case.

Then our z test value is the difference between proportions (.1) times std dev (.5)/square root of users (250)=.003

making our p value: .51197

 

Since this is well above .05, we accept that the proportion of internet users paying online is greater than 50%.

 

Hope that helps,

Deanna