Select all the relations which are not functions.
{(x, y) | x is the suggested retail price of particular car and y is price paid by a random car buyer for that car}
{(x, y) i x is a randomly selected person from the population who is a parent and y is a child of
that person}
{(x, y) | x is a randomly selected kentucky driver's license number and y is the identity of the person with that license number}
{(x, y) | x is a day of the year and y is a person born on that day}
{(x, y) is a randomly selected natural number greater than 8 and y is the remainder when that number is divided by 8}

Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining bismuth-210 transforms into another atom (polonium-210 in this case) each day. if you begin with 233 mg of bismuth-210, how much remains after 8 days?

Don't know how to find x given these segment lengths

Determine if the following statement is true or false. the normal curve is symmetric about its​ mean, mu. choose the best answer below. a. the statement is false. the normal curve is not symmetric about its​ mean, because the mean is the balancing point of the graph of the distribution. the median is the point where​ 50% of the area under the distribution is to the left and​ 50% to the right.​ therefore, the normal curve could only be symmetric about its​ median, not about its mean. b. the statement is true. the normal curve is a symmetric distribution with one​ peak, which means the​ mean, median, and mode are all equal.​ therefore, the normal curve is symmetric about the​ mean, mu. c. the statement is false. the mean is the balancing point for the graph of a​ distribution, and​ therefore, it is impossible for any distribution to be symmetric about the mean. d. the statement is true. the mean is the balancing point for the graph of a​ distribution, and​ therefore, all distributions are symmetric about the mean.