Answer:
Step-by-step explanation:
Given that the housing market has recovered slowly from the economic crisis of 2008. Recently, in one large community, realtors randomly sampled 38 bids from potential buyers to estimate the average loss in home value.
s = sample std deviation = 3000
Sample mean = 9379
Sample size n = 38
df = 37
Std error of sample mean =
confidence interval 95% = Mean ± t critical * std error
=Mean ±1.687*486.66 = Mean ±821.003
=(8557.997, 10200.003)
a) If std deviation changes to 9000 instead of 3000, margin of error becomes 3 times
Hence 2463.008
b) The more the std deviation the more the width of confidence interval.