Ch06: Chapter 6, Continuous Distributions

True/False

1. A uniform continuous distribution is also referred to as a rectangular distribution.

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Easy

2. The height of the rectangle depicting a uniform distribution is the probability of each outcome and it same for all of the possible outcomes

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

3. The area of the rectangle depicting a uniform distribution        is always equal to one.

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

4. Many human characteristics such as height and weight and many measurements such as variables such as household insurance and cost per square foot of rental space are normally distributed.

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Medium

5. Normal distribution is a skewed distribution with its tails extending to infinity on either side of the mean.

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Medium

6. Since a normal distribution curve extends from minus infinity to plus infinity, the area under the curve is infinity.

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Medium

7. A z-score is the number of standard deviations that a value of a random variable is above or below the mean.

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Medium

8. A normal distribution with a mean of zero and a standard deviation of 1 is called a null distribution.

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Medium

9. A standard normal distribution has a mean of zero and a standard deviation of one.

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Easy

10. The standard normal distribution is also called a finite distribution because its mean is zero and standard deviation one, always.

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Medium

11. In a standard normal distribution, if the area under curve to the right of a z-value is 0.10, then the area to the left of the same z-value is -0.10.

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Medium

12. Binomial distributions in which the sample sizes are large may be approximated by a Poisson distribution.

Ans:

Response: See section 6.3, Using the Normal Curve to Approximate Binomial Distribution Problems

Difficulty: Medium

13. A correction for continuity must be made when approximating the binomial distribution problems using a normal distribution.

Ans:

Response: See section 6.3, Using the Normal Curve to Approximate Binomial Distribution Problems

Difficulty: Medium

14. If arrivals at a bank followed a Poisson distribution, then the time between arrivals would follow a binomial distribution.

Ans:

Response: See section 6.4, Exponential Distribution

Difficulty: Hard

15. For an exponential distribution, the mean is always equal to its variance.

Ans:

Response: See section 6.4, Exponential Distribution

Difficulty: Hard

Multiple Choice

16. If x is uniformly distributed over the interval 8 to 12, inclusively (8  x  12), then the height of this distribution, f(x), is __________________.

a) 1/8

b) 1/4

c) 1/12

d) 1/20

e)  1/24

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Easy

17. If x is uniformly distributed over the interval 8 to 12, inclusively (8  x  12), then the mean of this distribution is __________________.

a) 10

b) 20

c) 5

d) 0

e) unknown

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

18. If x is uniformly distributed over the interval 8 to 12, inclusively (8  x  12), then the standard deviation of this distribution is __________________.

a) 4.00

b) 1.33

c) 1.15

d) 2.00

e) 1.00

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium