If one wants to test whether there is a difference in mean scores before and after an exam, which will be an appropriate test to use?
a) one sample z test
b) one sample t test
c) paired t test
d) two sample independent t test
If X is a random variable following a Uniform(a,b) distribution, which option represents an approxi- mate shape of its density function?
a) straight vertical line between a and b
b) straight horizontal line between a and b
c) symmetric U shaped curve between a and b
3. LetX∼N(20,1). WhatisP(X>20)?
a) 0.25
b) 0.5
c) 0.75
d) 0.99
If the data is in the form of a frequency table, it is best described using a:
a) histogram
b) pie-chart
c) stem and leaf plot
d) boxplot
1. Answer: Option C paired t test
To compare difference between population means before and after an trial or experiment, we use paired t-test
2. Answer: Option C Symmetric U shaped curve between a and b
Since it is continuous uniform distribution with values lies between a and b, hence frequency curve will be U shaped with values symmetrically distributed between range a and b
3. Answer: Option B 0.5
X ~ N(20,1)
P(x>20) = P[(x - 20) / 1 > (20 - 20) / 1]=P(z > 0) = 1-P(z < 0) = 1 - 0.5 = 0.5
4. Answer: Option A Histogram
Histogram helps in identifying distribution of data represented in frequency table i.e whether data is unimodal (one mode value) or bimodal (exists two mode values) or symmetrical or skewed as well as if it is skewed then whether it is positively or negative skewed.
If one wants to test whether there is a difference in mean scores before and after...
1. If one wants to test whether there is a difference in mean scores before and after an exam, which will be an appropriate test to use? a) one sample z test b) one sample t test c) paired t test d) two sample independent t test
Multiple Choice Questions Choose the one alternative that best completes the statement or answers the question (2.5 points each). You do not need to justify your answers. A If one wants to test whether there is a difference in mean scores before and after an exam, which will be an appropriate test to use? a) one sample z test b) one sample t test c) paired t test d) two sample independent t test B If X is a random...
A. Let X ~ N(20,1). What is P(X > 20) ? a) 0.25 b) 0.5 c) 0.75 d) 0.99 B If the data is in the form of a frequency table, it is best described using a: a) histogram b) pie-chart c) stem and leaf plot d) boxplot
2. If X is a random variable following a Uniform(a,b) distribution, which option represents an approxi- mate shape of its density function? a) straight vertical line between a and b b) straight horizontal line between a and b c) symmetric U shaped curve between a and b d) symmetric inverse U shaped curve between a and b
If X is a random variable following a Uniform(a,b) distribution, which option represents an approxi- mate shape of its density function? a) straight vertical line between a and b b) straight horizontal line between a and b c) symmetric U shaped curve between a and b d) symmetric inverse U shaped curve between a and b
The boxplot of the exam scores for the students in an introductory statistics course is given below. The distribution of the scores is 30 40 50 60 70 Score 80 90 100 Symmetric and bell-shaped Positively skewed O negatively skewed Symmetric but not bell-shaped A Ph.D. graduate has applied for a job with two universities: A and B. The graduate feels that she has a 60% chance of receiving an offer from university A and a 50% chance of receiving...
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