Find the critical value, t, for c=0.90 and n=10. 1.813 O 1.833 2.281 O 2.262 Determine the margin of error in estimating the population mean, . A sample of 81 college students yields a mean annual income of $3419. Assuming that a $941, find the margin of error in estimating at the 99% level of confidence. H $578 O $192 O $270 $381 25 packages are randomly selected from packages received by a parcel service. The sample has a mean weight of 23.8 pounds. Assume that a 3.4 pounds. What is the 95% confidence interval for the true mean weight, , of all packages received by the parcel service? 22.3 to 25.3 pounds 22.6 to 25 pounds O 22.4 to 25.2 pounds O 22.5 to 25.1 pounds