Assuming a population standard deviation of seven hours, what is the required sample size if the error should be less than a half hour with a 95% level of confidence?

Anew shopping mall is gaining in popularity. every day since it opened, the number of shoppers is 5% more than the number of shoppers the day before. the total number of shoppers over the first 10 days is 1258 how many shoppers were on the first day?

The longer leg of a 30-60-90 trangle is 18

Y= a(x-3)squared-1 what is the value of a