Answer:
The margin of error would decrease
Explanation:
Assuming the sample size Gallup used previously is less than 1500
Margin of error = t×sd/√n
From the formula above, the margin of error varies inversely as the square root of sample size
The smaller the sample size the larger is the margin of error and the larger the sample size the smaller is the margin error
Since the sample size increased the margin of error would decrease