The average burning times of American Standard lightbulbs (made in China) are normally distributed, with a mean of 1,300 hr and a standard deviation of 130 hr, according to quality control studies. A company installs a large number of these bulbs at the same time. After what amount of time should we expect 7.5% of them to burn out? (Hint: This will split the total area under the normal curve into an area of 0.0750 on the left-hand tail and 0.9250 on the other.)

Mistaking a legitimate program for a virus is a ____________

a. Heuristic error b. False negative c. False positive d. None of the above

Match each item with a statement below.

A. An authoritative name server that stores the primary copies of zone records. B. Enables you to create an alias for a host. C. A resource record containing basic information about a zone. D. Servers that enable you to forward unresolved queries to an offsite DNS server and then cache the results on your local DNS server. E. Identifies mail servers (mail exchangers) for a zone. F. Maintains a copy of the master zone file that's used as a backup. G. Used to resolve a hostname to an IPv4 address for locating a resource. H. Control the Internet's top-level domains (TLDs). I. Used to resolve an IPv4 address to its hostname.