QNT275-A quantitative variable is the only type

1.A quantitative variable is the only type of variable that can:

1. be used to prepare tables
2. have no intermediate values
3. assume numeric values for which arithmetic operations make sense
4. be graphed

2.A qualitative variable is the only type of variable that:

1. cannot be graphed
2. can assume an uncountable set of values
3. cannot be measured numerically
4. can assume numerical values

3.The following table gives the cumulative frequency distribution of the commuting time (in minutes) from home to work for a sample of 400 persons selected from a city.

Time (minutes) / f

0 to less than 10 / 64

0 to less than 20 / 155

0 to less than 30 / 217

0 to less than 40 / 293

0 to less than 50 / 349

0 to less than 60 / 400

1. The sample size is:
2. The percentage of persons who commute for less than 30 minutes, rounded to two decimal places, is:%
3. The cumulative relative frequency of the fourth class, rounded to four decimal places, is:
4. The percentage of persons who commute for 40 or more minutes, rounded to two decimal places, is:%
5. The percentage of persons who commute for less than 50 minutes, rounded to two decimal places, is:%
6. The number of persons who commute for 20 or more minutes is:

4.The temperatures (in degrees Fahrenheit) observed during seven days of summer in Los Angeles are:

78 99 68 91 102 75 85

1. The range of these temperatures is:
2. The variance of these temperatures, rounded to three decimals, is:
3. The standard deviation, rounded to three decimals, of these temperatures is:

5.The following table gives the two-way classification of 500 students based on sex and whether or not they suffer from math anxiety.

Suffer From Math Anxiety

Sex yes no

Male 156 84

Female 179 81

(round your answer to three decimal places, so 0.0857 would be 0.086) on A-D

1. If you randomly select one student from these 500 students, the probability that this selected student is a female is:

1. If you randomly select one student from these 500 students, the probability that this selected student suffers from math anxiety is:

1. If you randomly select one student from these 500 students, the probability that this selected student suffers from math anxiety, given that he is a male is:

1. If you randomly select one student from these 500 students, the probability that this selected student is a female, given that she does not suffer from math anxiety is:

5a.Which of the following pairs of events are mutually exclusive?

1. Female and male
2. Male and no
3. Male and yes
4. No and yes
5. Female and no
6. Female and yes

5b.Are the events "Has math anxiety" and "Person is female" independent or dependent? Detail the calculations you performed to determine this. (Dependent or Independent)

6.For the probability distribution of a discrete random variable x, the sum of the probabilities of all values of x must be:

1. equal to 1
2. in the range zero to 1
3. equal to 0.5
4. equal to zero

7.The following table lists the probability distribution of a discrete random variable x:

X 2 / 3 / 4 / 5 / 6 / 7 / 8

P(x) 0.15/ 0.34/ 0.24/ 0.13/ 0.06/ 0.06/ 0.02

1. The mean of the random variable x is:
2. The standard deviation of the random variable x, rounded to three decimal places, is:

8.

1. The daily sales at a convenience store produce a distribution that is approximately normal with a mean of 1160 and a standard deviation of 142.
2. The probability that the sales on a given day at this store are more than $1,405, rounded to four decimal places, is:
3. The probability that the sales on a given day at this store are less than $1,305, rounded to four decimal places, is:
4. The probability that the sales on a given day at this store are between $1,200 and $1,300, rounded to four decimal places, is:

9.The width of a confidence interval depends on the size of the:

1. population mean
2. margin of error
3. sample mean
4. none of these

10.A sample of size 62 from a population having standard deviation ? = 53 produced a mean of 246.00. The 95% confidence interval for the population mean (rounded to two decimal places) is:

1. The lower limit is

1. The upper limit is

11.The null hypothesis is a claim about a:

1. statistic, where the claim is assumed to be true until it is declared false
2. population parameter, where the claim is assumed to be false until it is declared true
3. statistic, where the claim is assumed to be false until it is declared true
4. population parameter, where the claim is assumed to be true until it is declared false

12.The alternative hypothesis is a claim about a:

1. statistic, where the claim is assumed to be false until it is declared true
2. population parameter, where the claim is assumed to be true until it is declared false
3. population parameter, where the claim is assumed to be true if the null hypothesis is declared false
4. statistic, where the claim is assumed to be true if the null hypothesis is declared false

13.In a one-tailed hypothesis test, a critical point is a point that divides the area under the sampling distribution of a:

1. statistic into one rejection region and one nonrejection region
2. population parameter into one rejection region and one nonrejection region
3. statistic into one rejection region and two nonrejection regions
4. population parameter into two rejection regions and one nonrejection region

14.In a two-tailed hypothesis test, the two critical points are the points that divide the area under the sampling distribution of a:

1. population parameter into two rejection regions and one nonrejection region
2. statistic into one rejection region and two nonrejection regions
3. population parameter into one rejection region and one nonrejection region
4. statistic into two rejection regions and one nonrejection region

15.In a hypothesis test, a Type I error occurs when:

1. a false null hypothesis is not rejected
2. a true null hypothesis is rejected
3. a true null hypothesis is not rejected
4. a false null hypothesis is rejected

16.In a hypothesis test, a Type II error occurs when:

1. a true null hypothesis is not rejected
2. a false null hypothesis is rejected
3. a false null hypothesis is not rejected
4. a true null hypothesis is rejected

17.In a hypothesis test, the probability of committing a Type I error is called the:

1. significance level
2. beta error
3. confidence interval
4. confidence level