Practice Questions 10.2 [NOT ON FINAL]

binomial data: What statistic for continuous data is analogous to the sample proportion?

A)  The sample average (x̄).
B) The sample median (M).
C) The sample standard deviation (s).
D) The sample inter-quartile range (IQR).

binomial data: What characteristic of a column of data does proportion measure?

A) The count of the column of data values.
B) The shape of the column of data values.
C) The spread of the column of data values.
D)  The location of the column of data values.

binomial data: How is the sample proportion calculated?

A) Same as the sample standard deviation, use a sum-of-squares table.
B) Same as the sample count, count all the data values.
C) Same as the sample median, rank the data values and use the three-step method to find percentiles.
D)  Same as the sample average, add up the data values and divide by n.

binomial data: What data values are appropriate to calculate the sample proportion?

A)  Only two data values (0 and 1).
B) Any data value that can be converted into numbers (1, 2, 3, etc.).
C) Data values taken from binomial individuals.
D) Any two data values (male and female).

binomial data: How is the standard error of the sample proportion

A)  The standard error of the sample proportion equals the standard deviation of the data values
B) The standard error of the sample proportion must be given in the problem.
C)  Same as the standard error of the sample average, (standard deviation / √n)
D)  By dividing the standard deviation of the data values by the degrees of freedom.

binomial data: What is the shape of the sample proportion?

A)  The shape of the normal curve, after the condition to use the normal approximation is met.
B) Always the shape of the binomial curve.
C) The shape of the t-curve, after the condition to use the t-distribution is met.
D) Always the shape of the normal curve. 

binomial data: What does the statistical word proportion mean?

A) The proportion of the two data values in the column of data.
B) The proportion in a binomial event.
C)  The proportion of successes in a binomial experiment.
D) The proportion of zero's (0) in the binomial experiment.

binomial data: Shouldn't the binomial histogram be approximated by the t-curve, since the population standard deviation is not known?

A) It depends on how many data values are in the column of data.
B)  No, because it is an approximation and the z-curve is a better fit.
C) Yes, the t-curve should be used, as the z-curve is archaic methodology.
D) The t-curve would be used if it were possible to calculate the degrees of freedom.

binomial data: How many tail(s) situation is a confidence interval for the population proportion?

A) A confidence interval for proportion is meaningless since it can have values less than zero (0) or greater than one (1).
B) Confidence intervals are designed to always be a one-tail to the right situation.
C)  It is always a two-tail situation.
D) It can be either one-tail or two-tail depending on the question.

binomial data: Select the two components of a confidence interval for the population proportion?

A) The width of the confidence interval.
B) The direction of the confidence interval.
C) The location of the confidence interval.
D) The margin of error of the confidence interval.

binomial data: A statistics instructor at a local college sampled 100 of her students and found that 25 of them actually liked statistics. What is the 95% confidence interval for the population proportion of students liking statistics?

A) CI = (0.20, 0.30)
B)  CI = (0.16, 0.33)
C) CI = (0.34, 0.17)
D) CI = (0.14, 0.36)

binomial data: Using confidence intervals, how could you tell if the means of two, or more, populations might be the same.

A)  The population means might be the same if the confidence intervals overlapped.
B) The population means might be the same if the confidence intervals are close to each other.
C) The population means might be the same if the margins of error are equal.
D) The population means might be the same if the locations are equal.

binomial data: In the confidence interval below, what is the sample average / the margin of error?
(102, 110)

A) Sample average = 106 / Margin of error = 8
B) Sample average = 106 / Margin of error = 6
C) Sample average cannot be determined with this information / Margin of error = 8
D)  Sample average = 106 / Margin of error = 4

binomial data: A mathematics instructor at a local college felt that more students actually like mathematics than the 25% of students who like statistics. To prove her case, she sampled 250 of her students and found that 25 of them actually liked mathematics. What is the 95% confidence interval for the population proportion of students liking mathematics?

A) CI = (0.16, 0.33)
B) CI = (0.05, 0.15)
C) CI = (0.07, 0.13)
D)  CI = (0.06, 0.14)

binomial data: A study was performed where 74 patients with ulcers were prescribed a drug designed to treat ulcers. After six weeks 42 of the patients reported healing of their ulcer giving a sample proportion of 0.57. The FDA will approve a drug if more than 50% of people experience healing. Should the FDA approve this drug?

A)  No, because the population proportion could be as low as 0.42
B) No, because half of the possible values for population proportion are less than 0.57
C) No, because the population proportion could be as low as 0.24
D) No, because the condition to use the normal approximation is not met.

binomial data: Which two statements are shown in the Happy Clown with Glasses memory device?

A) The critical value is calculated from the test statistic.
B) Alpha is divided by the number of tails to get the critical value.
C) p-Value is the area in the tail(s) from the critical value.
D) Area from a table is multiplied by the number of tails to get p-value.

binomial data: Select the steps which are part of the General Method to do a hypothesis test.

A) Step A: Abstract.
B) Step 1: Theorize.
C) Step 2: Analyze.
D) Step 3: Infer.

binomial data: What information goes to make the Null Hypothesis / the Alternative Hypothesis?

A) The researcher's belief / The belief being tested.
B) The theoretical value / The actual value.
C) The tested value / The believed value.
D) The status quo belief / The researcher's belief.

binomial data: For a null hypothesis that has the less than sign (<), what type of tail test is this?

A) A one-tail test to the left.
B)  Not a valid null hypothesis.
C) A one-tail test to the right.
D) A two-tail test.

binomial data: A prior study of pet owners found that 37% of them talked to their pet on the answering machine. Hard to believe, so 150 pet owners were surveyed and 54 of them did talk to their pets like this. Analyzing this information with a hypothesis test, select the appropriate responses below for testing if less than 37% of pet owners talk to their pet this way? (α = 0.05}

A) The proportion has not changed, because the test statistic z = -0.25
B) The proportion is less, because the test statistic t = 0.25 
C) The proportion is less, because p = 0.0 
D) The proportion has not changed, because p-value = 0.3632

binomial data: A prior study found that 85% of adult Americans ate a salad at least once per week. With the convenience of fast food this percentage does not seem right, so a local statistics instructor queried 225 college students and found that 175 students did eat salad at least once each week. Analyzing this new information with a hypothesis test, select the appropriate responses below for testing if 85% is the proper percentage? (α = 0.10}

A)  85% is not the proper proportion, because the test statistic z = -3.03
B)  85% is not the proper proportion, because p-value= 0.0012
C)  85% is not the proper proportion, because the alternative hypothesis was not rejected.
D)   85% is not the proper proportion, because the null hypothesis was not rejected.

binomial data: A famous basketball player was known to struggle with free throws, making only 43.8% of them. His coach sent him to a free throw specialist who worked with him for five days. Then the basketball player shot 80 free throws and made 39 of them. Analyzing this information with a hypothesis test, select the appropriate responses below for testing if the specialist improved the players percentage? (α= 0.05)

A) The percentage did not improve, because p-value = 0.1867.
B) The percentage did improve, because p= 0.49.
C) The percentage did not improve, because the test statistic z = 0.89.
D) The percentage did not improve, because the critical value z = 1.96.

binomial data: In May 1999 (internet by telephone dial-up only), 57.8% of households watched TV during prime time. Now (internet everywhere), 1,025 households were questioned and 575 households watched TV during prime time. Analyzing this information with a hypothesis test, select the appropriate responses below to answer if the availability of the internet has affected TV viewing. (α = 0.10)

A)  Prime time TV viewing has not been affected, because p-value = 0.2714
B) Prime time TV viewing has not been affected, because the test statistic z = -1.10
C) Prime time TV viewing has not been affected, because p-value = 0.1357
D) Prime time TV viewing has not been affected, because the test statistic z = 1.64