29. A manufacturer knows that their items have a normally distributed lifespan, with a mean of 11.2 years, and standard deviation of 2.1 years. The 7% of items with the shortest lifespan will last less than how many years? (Show all work)

An IQ test has a mean of 100 and a standard deviation of 15. Which is more unusual, an IQ of 85 or an IQ of 120? what is the z-score for IQ 85   what is the z-score for IQ 120

Suppose that the lengths of pregnancies are normally distributed with a mean of 271 days and a standard deviation of 10 days.  find the percentage of pregnancies that are longer than 254 days. For your intermediate computations, use four or more decimal places. Give your final answer to two decimal places (for example 98.23%).

SAT exam math scores are normally distributed with mean 523 and standard deviation 89. If 2 million students took the SAT last year, about how many of them scored at least a 660?