c Based only on this confidence interval do the sample data

c. Based only on this confidence interval, do the sample data suggest that more than half of the population favored Santos?

Solution

a. Yes the conditions met for the confidence interval procedure to be valid with these data .

Generally, the sampling distribution will be approximately normally distributed when the sample size is greater than or equal to 30.

Hence,

b.

z for 90% = 1.645

p = 0.54

n = 1208

Margin of error = z * sqrt(p(1-p)/n)

= 1.645 * sqrt ((0.54 * 0.46)/1208)

= 0.0236

Confidence Interval = ( 0.54 - 0.0236 , 0.54+0.0236 )

= (0.5164 , 0.5636) Answer

c.

Yes , based only on this confidence interval, the sample data suggest that more than half of the population favored Santos.