Apharmacy wants to survey its customers to find out which brand of toothpaste they prefer. which survey methods are likely to be biased?
choose all answers that are correct.
a.
a survey is sent to the customers who are on the pharmacy’s frequent buyer list.
b.
one hundred people from the pharmacy’s customer list are selected at random, called on the phone, and asked.
c.
those customers who buy toothpaste with a coupon are selected, and the toothpaste brand they purchased is recorded.
d.
every 10th customer who enters the pharmacy on 1 day is selected and asked.

Jose predicted that he would sell 48 umbrellas. he actually sold 72 umbrellas. what are the values of a and b in the table below? round to the nearest tenth if necessary

The area of a circle is equal to 1 dm². find the radius of the circle.

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) =