Expert answer:the independent variable
Solved by verified expert:Need all answers
quiz_1_stat_200.pdf
Unformatted Attachment Preview
DQuiz 1 (4 points per question; maximum score 40 points for Quiz 1)
You must show you work if a problem involves more than one step of logical inferences and/or
numerical manipulations.
1. A random sample is one _D__
a. That is haphazard
b. That is unplanned
c. That ensures that there will be no uncertainty in the conclusions
d. In which every unit of a particular size has an equal probability of being selected
2. Stratified sampling_D__
a. Can be more representative than simple randomized sampling
b. Can be used if the population has a number of distinct groups
c. Is done by randomly sampling from subgroups in a way that is proportional to their
size in the population
d. All of the above
3. In an experiment on the effect of exercise on memory, the independent variable is
_C_(choose only one answer)
a. Recall score on a memory test
b. Gender of the subjects
c. Number of hours of exercise
d. Gender of the experimenter
4. For the scores 3, 5, 8, 10, 14, 17, 21, 25, calculate the 75th percentile using the following
formula: R = P/100 x (n+ 1)
R= 75/100x(8+1) = 6.75
a. 6.75
b. 20
c. 17
d. 21
5. The area under the curve of a probability distribution is _____
a. 0
b. 100
c. .68
d. 1
6. Sometimes we need to use median instead of mean to better measure central tendency
in a sample if
a. The sample has a large variance
b. We have measurement error when collecting the sample
c. The sample mean is too small
d. The distribution is extrenely skewed.
7. In a bell-shaped distribution, changing ___can make the shape of distribution flatter, or
skinner; and changing ___ can shift the central location of distribution to the left or to
the right.
a. Mean, variance
b. Range, standard deviation
c. Mode, range
d. Mean, range
e. Mode, variance
f. Variance, mean
8. If a distribution is left-skewed, its mean is usually___ its median
a. smaller than
b. bigger than
c. equal to
d. we can not know
9. A researcher collected BMI (Body Mass Index) of 50 students in an Engineering school.
He found the mean BMI was much smaller than the median BMI. The reason for this
might be___
a. Several students had much larger BMI scores than the rest
b. Several students had much smaller BMI scores than the other students
c. The researcher made some measurement errors
d. All the students had smaller BMI scores, compared to national average
10. A large batch of several million coins was recovered from an excavation site. Students
who participated in the operation want to test whether the coind are unbiased (i.e. equal
likely to show head or tail when tossed). They conducted 2 experiemnts: Exp-1: 100 coins
were randomly selected from the batch, and then each was tossed once. Exp-2: one coin
was randomly selected from the batch, and then tossed 100 times. Specifically, the
question they are interested is that If every coin in the batch could be tested for
unbiasedness, they would be able to know whether these coins are unbiased.
Select all the answers that is false ________________.
a. Since each eperiement has a sample size 100, they can answer the the question
equally well.
b. Since the coins were randomly selected from the batch, they can answer the question
eqally well.
c. Both data sets contain the same information to answer any question about the
unbiasedness of the coins.
d. The data from Exp-1 can answer the question better that Exp-2.
…
Purchase answer to see full
attachment
How it works
- Paste your instructions in the instructions box. You can also attach an instructions file
- Select the writer category, deadline, education level and review the instructions
- Make a payment for the order to be assignment to a writer
- Download the paper after the writer uploads it
Will the writer plagiarize my essay?
You will get a plagiarism-free paper and you can get an originality report upon request.
Is this service safe?
All the personal information is confidential and we have 100% safe payment methods. We also guarantee good grades