A random sample of 25 round trip flights between Philadelphia and Dallas has an average airfare of 393.50 with a sample Standard Deviation of $50.30. The critical value for an 80% confidence interval around this sample mean

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

Write an introductory paragraph for this corrie ten boom and her family were faced with some difficult choices after hitler came to power. some family members paid the ultimate price. write a carefully thought-out paper of at least 200 words dealing with the following concepts: --how should a christian act when evil is in power? --what do you think it would be like to live in an occupied country? remember to proofread anything you write thoroughly.

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25