# Statistic exam | Mathematics homework help

- The portion of the universe that has been selected for analysis is called:

Answer a sample |

a frame |

a parameter |

a statistic |

**Question 2**

One of the advantages of a pie chart is that it clearly shows that the total of all the categories of the pie adds to 100%.

Answer

True

False

**Question 3**

Which of the 4 methods of data collection is involved when a person counts the number of cars passing designated location on the Los Angeles freeway system?

Answer published sources |

experimentation |

surveying |

observation |

**Question 4**

The coefficient of variation is a measure of the central tendency in the data.

Answer

True

False

**Question 5**

Which of the following is NOT a measure of central tendency?

Answer the arithmetic mean |

the geometric mean |

the mode |

the interquartile range |

**Question 6**

A Pareto diagram is a bar chart in which the bars are naturally arranged with a decreasing pattern:

Answer

True

False

-Question 7

If two events are collectively exhaustive, what is the probabiltiy that one or the other occurs?

Answer 0 |

.50 |

1.00 |

Can not be determined with the information given |

**Question 8**

The cross-tabulation of two categorical variables leads to a contingency table:

Answer

True

False

Question 9

A business venture can result in the following outcomes (with their corresponding chance of occuring in parenthesis); Highly Successful (10%), Successful (25%), Break Even (25%), Disappointing (20%), and Highly Disappointing (?). If these are the only outcomes possible for the business venture, what is the chance that the business venture will be considered Highly Disappointing?

4 points

**Question 10**

A population consists of all the possible objects to be studied:

Answer

True

False

4 points

**Question 11**

An economics professor bases his final grade on homework, two midterm examinations, and a final examination. The homework counts 10% toward the final grade, while each midterm counts 25%. The remaining porttion consists of the final exam. If a student scored 95% in homework, 70% on the first midterm, 96% on the second midterm, and 72% on the final exam, his final average is 79.8%

Answer

True

False

4 points

**Question 12**

If event A and Event B cannot occur at the same point in time, then events A and B are said to be

Answer mutually exclusive |

statistically independent |

collectively exhaustive |

none of the above |

4 points

**Question 13**

Thirty-six of the staff of 80 teachers at a local intermediate school are certified in Cardio-Pulmonary Resuscitation (CPR). In 180 days of school, about how many days can we expect that the teacher on bus duty will likely be certified in CPR

Answer 5 Days |

45 Days |

65 days |

81 Days |

4 points

**Question 14**

If we randomly draw a ball from a bag with a finite number of balls in it, then put the ball back into the bag and randomly draw another ball from the bag, this is an example of sampling with replacement

Answer

True

False

4 points

**Question 15**

The Standard Normal distribution has a mean of 1 and a standard deviation of 1.

Answer

True

False

4 points

**Question 16**

Marginal probability is also called

Answer Simple probability |

Conditional probability |

Joint probability |

Bayes’ theorem |

4 points

**Question 17**

If n = 10 and p = 0.70, then the standard deviation of the binomial distribution is

Answer 0.07 |

1.45 |

7.00 |

14.29 |

4 points

**Question 18**

In its standardized form, the normal distribution

Answer has a mean of 0 and a standard diviation of 1. |

has a mean of 1 and a variance of 0. |

has an area equal to .05 |

cannot be used to aprroximate discrete probability distribution. |

4 points

**Question 19**

The “empirical rule” for the bell-shaped curve states that the percentage of data points falling within three standard deviations away from the mean is 99.7%

Answer

True

False

4 points

**Question 20**

Distribution 1 is a skewed distribution and Distribution 2 is a symmetric distribution (not Normal distribution). Similar sample sizes will be required for the sample mean of random samples from the two distributions to have an approximate Normal distribution.

Answer

True

False

4 points

**Question 21**

The null hypothesis Ho always contains an equal sign

Answer

True

False

4 points

**Question 22**

If we know that the length of time it takes a college student to find a parking spot in the library parking lot follows a normal distribution with a mean of 3.5 minutes and a standard deviation of 1 minute, find the probability that a randomly selected college student will find a parking spot in the library parking lot in less than 3 minutes.

Answer 0.3551 |

0.3085 |

0.2674 |

0.1915 |

4 points

**Question 23**

If we know that the length of time it takes a college student to find a parking spot in the library parking lot follows a normal distribution with a mean of 3.5 minutes and a standard deviation of 1 minute, find the point in the distiribution that 75.8% of the college students **exceed **when trying to find a parking spot in the library parling lot.

Answer

2.8 minutes |

3.2 minutes |

3.4 minutes |

4.2 minutes |

4 points

**Question 24**

The fact that the sample means are less variable than the population data can be observed form the standard error of the mean.

Answer

True

False

4 points

**Question 25**

In left-skewed distribution, the median is

Answer
equal to the mean |

greater than the mean |

less than the mean |

none of the above |