7. Use R: Suppose the yearly income of people in Minnesota is normally distributed with mean 45,700 and standard deviation 2830. Find the probability that 10 randomly selected people have mean (Xbar) income between 44000 and 48000.

Assume a standardized IQ test exists that possesses a normal distribution and has a mean score of 100 with a standard deviation of 10 What is the probability of selecting someone from the general population at random who would

the annual precipitation has normal distribution with a mean of 109 and standard deviation of 10. What is the probability that the mean annual precipitation during 25 randomly selected years will be less than 110.2 in

Suppose that the amount of time that students spend studying in the library in one sitting is normally distributed with mean 49 minutes and standard deviation 22 minutes. A researcher observed 44 students who entered the library to study. Round all answers to 4 decimal places where possible. Find the probability that the randomly selected 44 students will have a total study time more than 1936 minutes.  The top 20% of the total study time for groups of 44 students will be given a sticker that says "Great dedication". What is the least total time that a group can study and still receive a sticker? minutes What is the distribution of ∑x∑x? ∑x∑x ~ N(