Hoping to lure more shoppers downtown, a city builds a new public parking garage in the central business district. The city plans to pay for the structure through parking fees. For a two-month period (45 weekdays), daily fees collected averaged $1,264, with a standard deviation of $120. The 95% confidence interval for the mean daily income is $1,234 to $1,294. Complete parts a through d. Click here to view a table of the normal distribution critical values. (a) Someone suggests that the city use its data to create a 99% confidence interval instead of the 95% interval first created. Would this interval be better for the city planners O A. No, this would be a narrower interval containing fewer values for the mean daily income. O B. Yes, this would be a narrower interval containing fewer values for the mean daily income. O C. Yes, this would be a wider interval containing more values for the mean daily income. ✔D. No, this would be a wider interval containing more values for the mean daily income. (b) How would the 99% confidence interval be worse for the city planners? ✓ Planners need a small interval to make an accurate estimate to better serve their planning. O B. Planners need a large interval because they need to plan for over spending. O C. Planners need a large interval because they need to plan for under spending. O D. The 99% confidence interval would be better for the city planners. (c) How could city planners achieve an interval estimate that would better serve their planning needs? A. City planners could collect data over more days. O B. City planners could increase the parking fees. O C. City planners could decrease the parking fees. O D. City planners could collect data over fewer days. (d) How many days' worth of data must planners collect to have 99% confidence of estimating the true mean to within $7? (Use a z-interval to simplify the calculations.) Planners must collect 81 days' worth of data. (Round up to the nearest day.) normal distribution critical values D 0.6745 0.7063 0.7388 0.7722 0.8064 0.8416 0.8779 0.9154 0.9542 0.9945 1.0364 1.0803 1.1264 1.1750 1.2265 1.2816 1.3408 1.4051 1.4758 1.5548 1.6449 1.7507 1.8808 1.9600 2.0537 2.3263 2.5758 2.8070 3.0902 3.2905 3.7190 3.8906 4.2649 4.4172 P(Z =-1) 0.25 0.24 0.23 0.22 0.21 0.20 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.025 0.02 0.01 0.005 0.0025 0.001 0.0005 0.0001 0.00005 0.00001 0.000005