Stats Exam 2

The price of gold was $1061 per oz on Dec 31 and has risen 14.78% since that time. What is the price per oz now

1061*0.1478= 156 1061+156=1218

33 45 65 50 65 48 60 55 Find the third quartile (Q3) A. 62.5 B. 46.5 C. 52.5 D. 45 E. 50

A. 62.5

Here is the data set 14, 8, 10, 7, 6. Find the mean A. 9 B. 8 C. 14 D. 45 E. 6

A. 9 add all numbers together then divide sum by how many numbers there are.

What does seasonal adjustment means A. when we ignore the effects of one-time events such as strikes and hurricanes B. we report the average for this month over several past years, not just this month's data C. we report the average for the past four months, maybe just this month's data D. data are seasonally adjusted if we take out changes that occur in about the same size and time every year

Answer: data are seasonally adjusted if we take out changes that occur in about the same size and time every year

Is it hard to measure "intelligence" To do it the easy way, one can measure the circumference of the head, just above the ear in inches, and call the results "intelligence" Not only is this method easy, it gives nearly the same number every time one reports the same number every time one repeats the measurement on the same person. Measuring intelligence this way is A. not reliable but not valid B. valid but not reliable C. highly reliable but not valid D. both valid and highly reliable

Answer: highly reliable but not valid

an office worker sets her coffee maker to start brewing at 5:30 am. On some mornings it starts five minutes early. On others it starts 10 mins early. On others it starts 10 mins early. It is always early, but there is no way of telling when the coffee will start to be made or finished. The time on the coffee maker is: A. biased B. imprecise C. unreliable D. a sampling error E. invalid

Answer: invalid

In order to be correct, a line graph of the number of suicides per year in the USA must have A. number of suicides on the horizontal B. either suicides or years on the horizontal C. bars of equal width D. years on the horizontal line

Answer: years on the horizontal line

33 45 65 50 65 48 60 55 Find the first quartile (Q1) A. 62.5 B. 46.5 C. 52.5 D. 45 E. 50

B 46.5

Here is the data set 14, 8, 10, 7, 6. Find the standard deviation A. 9 B. 8 C. 3.16 D. 2.83 E. 6

C. 3.16 Find the mean Subtract each number by the sum square that answer add all those answers together divide by one less than the numbers that are presented find the square root of that

33 45 65 50 65 48 60 55 find the median A. 62.5 B. 46.5 C. 52.5 D. 45 E. 50

C. 52.5

To illustrate the talk you are giving, you want to make graph to compare the consumption of alcohol per person for several countries. For example, this is 2.87 gallons per person in France and 1.74 gallons per person in United States. You would make a A. histogram B. line graph C. pie chart D. Bar Graph

Correct: Bar graph

A study in which information about individual subjects are never made public is said to be 1. anonymous 2. blind 3. unbiased 4. replicated 5. confidential

Correct: confidential

Professor Duffy wishes to study the relationship between people's zodiac sign and their political opinions. She asks the students filling out her questionnaire to put their names on the front so she can ask for some clarification of some answers later. However, she promises that no one other than she will find out who gave that answer. Prof Duffy is promising to 1. both anonymous and confidential 2. confidential 3. anonymous but not completely confidential 4. low reliability 5. confidential but not necessarily anonymous

Correct: confidential but not necessarily anonymous

Jack is enrolling human participants in a study that will test whether drivers stop more quickly for men or women in a crosswalk when the pedestrian is obeying the crossing signal. Because no one would sign up for the study if he were to tell them of its dangerous nature, he advertises it as a "study involving a walk outside" What principle is Josh violating? A.anonymity B. confidentiality C. placebo control D. informed consent

Correct: informed consent

Josh developed a new test of level of spiritual awareness for his course on religion of the world/ Any such tests should must have several versions because some people take the test more than once. Unfortunately, it turns out that the same person often gets very different scores, depending on which version of the test is offered, even when taking the version at the same time. The test suffers from 1. low reliability 2. large bias 3. confounding 4. large sampling errors

Correct: low reliability

7 member of a fraternity take a stats course. Here are their scores on the first exam 61 74 47 60 62 63 75 To present the distribution of the scores in a graph, you might chose a A, bar graph B. histogram C. line graph D. pie chart E. stemplot

E. stemplot

please look at the density curve

I'm sure you do not remember much if it and need it Part 2 of study guide

in the last half of 2015, the price of Apple Inc. (AAPL) common stock dropped from $126.60 per share to $105.26 per share. What percent decrease is this

[(new-old)/old] x 100 [(105.26-126.6)/126.6]x100= 6.86%

from 2010 to 2015, the average annual profit for Acme Floormat Company has increased from 1.5 mill to 10 mill

[(new-old)/old]*100= [(10-1.5)/1.5]*100= 567%

You make a graph to show how the cost of attending your school has increased since 1980. A good choice of graph is A. bar graph B. histogram C. line graph D. pie graph E. stemplot

line graph