Find counterexamples to each of these statements about congruences.
a) if ac ≡ bc (mod m), where a, b, c, and m are integers with m ≥ 2, then a ≡ b (mod m).
b) if a ≡ b (mod m) and c ≡ d (mod m), where a, b, c, d, and m are integers with c and d positive and m ≥ 2, then ac ≡ bd (mod m).

Using two or more complete sentences, describe how you can find a vector parallel to b=-2,3

The four students in the table below each recorded the time and distance traveled while exercising. exercising distance (miles) time (minutes) gia 2 30 harris 5 50 ian 3 40 jackson 4 80 which list ranks the students from fastest walker to slowest walker? jackson, gia, ian, harris harris, jackson, ian, gia harris, ian, gia, jackson jackson, harris, ian, gia

1. why is a frequency distribution useful? it allows researchers to see the "shape" of the data. it tells researchers how often the mean occurs in a set of data. it can visually identify the mean. it ignores outliers. 2. the is defined by its mean and standard deviation alone. normal distribution frequency distribution median distribution marginal distribution 3. approximately % of the data in a given sample falls within three standard deviations of the mean if it is normally distributed. 95 68 34 99 4. a data set is said to be if the mean of the data is greater than the median of the data. normally distributed frequency distributed right-skewed left-skewed