Could anyone help me with this ?

Yvaries inversely as x. y =12 when x=5. find y when x=4

Atest of sobriety involves measuring the subject's motor skills. a sample of 31 randomly selected sober subjects take the test and produce a mean score of 64.4 with a standard deviation of 2. a claim is made that the true mean score for all sober subjects is equal to 65. for each part below, enter only a numeric value in the answer box. for example, do not type "z =" or "t =" before your answers. round each of your answers to 3 places after the decimal point. (a) calculate the value of the test statistic used in this test. test statistic's value = (b) use your calculator to find the p-value of this test. p-value = (c) use your calculator to find the critical value(s) used to test this claim at the 0.2 significance level. if there are two critical values, then list them both with a comma between them. critical value(s) =

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $36.98. find the probability that a randomly selected bill will have an amount greater than $173, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?