If X ~ N(μ ,σ 2 ) , then the interquartile range (IQR) of X is ______.
1.35σ
1.35σ2
2σ
2σ 2
As you observe a normal probability plot for a random sample, if the plot
appears a nonlinear pattern with upward increasing manner, what does
the sample probably come from?
the population with a normal distribution
the population with a left skewed probability distribution
the population with a right skewed probability distribution
the population with a rectangle probability distribution
The main difference between the t and z statistic is that the t statistic
is not normally distributed like the z statistic
more variable than the z statistic
is less variable than the z statistic
has a mean of 1 and the z statistic has a mean of 0.
A polling company finds a 99% confidence interval of 0.357 ±0.045 who
prefer a certain brand of soda over the competition. If the company wishes
to estimate its market share within 0.010 with a 99% confidence interval,
how many people would they need to sample in order to calculate the
market share for this new bound?
1345
36490
8630
15953
If a researcher conducted a hypothesis test and rejected the null hypothesis
at α = 0.05 , would the null hypothesis be rejected again at α = 0.01 ?
No, because the confidence interval has changed
It may be rejected again, but it is not definite
Yes, because the confidence interval is lower
Yes, because the confidence interval is higher
Which of the following is not an assumption that must be made when
performing a small-sample test for hypothesis (μ1 −μ2 ) independent
samples?
The samples are randomly and independently selected from the
population.
Both sampled populations have relative frequency distributions that are
approximately normal.
The mean of each of the samples is approximately equal to the mean of
the populations from which they are taken.
The population variances are equal.
(18.9555, 21.1445)
(19.9552, 20.0448)
(19.0112, 20.9888)
(18.0165, 21.9835)
(0.103, 0.144)
(0.096, 0.161)
(0.011, 0.119)
(0.016, 0.121)
Two samples each of size 25 are taken from independent populations assumed
to be normally distributed with equal variances. The first sample has a mean
of 35.5 and standard deviation of 3.0 while the second sample has a mean of
33.0 and standard deviation of 4.0.
The pooled sample variance is ________.
3.5
12.25
12.5
15
Two samples each of size 25 are taken from independent populations assumed
to be normally distributed with equal variances. The first sample has a mean
of 35.5 and standard deviation of 3.0 while the second sample has a mean of
33.0 and standard deviation of 4.0.
What is the 95% confidence interval estimate for the difference in the two
population means?
(0.5412, 4.4637)
(0.4894, 4.5106)
(0.4405, 4.5595)
(0.1861, 4.8139)
Two samples each of size 25 are taken from independent populations assumed
to be normally distributed with equal variances. The first sample has a mean
of 35.5 and standard deviation of 3.0 while the second sample has a mean of
33.0 and standard deviation of 4.0.
(0.2479, 1.2765)
(0.4894, 4.5106)
(0.4405, 4.5595)
(0.7834, 4.0343)
If you conduct the one-way ANOVA for the data, the among-group
variation or SSA is ________.
0.7955
3.181875
1.1825
3.568875
Given the total variation SST = 4.364375, the ANOVA F statistic is
________.
0.729
1.084
10.763
3.271
When we perform the ANOVA F test, what will be the conclusion?
At the 0.05 level of significance, the mean ratios for the 4 neighborhoods
are not all the same.
At the 0.01 level of significance, the mean ratios for the 4 neighborhoods
are all the same.
At the 0.10 level of significance, the mean ratios for the 4 neighborhoods
are not significantly different.
At the 0.05 level of significance, the mean ratios for the 4 neighborhoods
are not significantly different from 0.
An economist is interested to see how consumption for an economy (in $
billions) is influenced by gross domestic product ($ billions) and aggregate
price (consumer price index). The Microsoft Excel output of this regression is
partially reproduced below.
When the economist used a simple linear regression model with
consumption as the dependent variable and GDP as the independent
variable, he obtained an r2 value of 0.971. What additional percentage of
the total variation of consumption has been explained by including
aggregate prices in the multiple regression?
98.2
11.1
2.8
1.1
An economist is interested to see how consumption for an economy (in $
billions) is influenced by gross domestic product ($ billions) and aggregate
price (consumer price index). The Microsoft Excel output of this regression is
partially reproduced below.
To test whether aggregate price index has a negative impact on
consumption, the P-value is ________?
0.0001
0.4165
0.8330
0.8837
Compute the χ 2 statistic for the contingency table.
3.8415
5.9418
9.4877
13.2767
When we perform the Chi-square test for the contingency table, what will
be the conclusion?
At the 0.05 level of significance, brand awareness of female TV viewers
and the gender of the spokesperson are independent.
At the 0.05 level of significance, brand awareness of female TV viewers
and the gender of the spokesperson are not independent.
At the 0.01 level of significance, brand awareness of female TV viewers
and the gender of the spokesperson are significantly dependent
At the 0.01 level of significance, brand awareness of female TV viewers
and the gender of the spokesperson are related.
(a) 試建立二因子變異數分析表。(12%)
(b) 試以5%顯著水準,分別檢定年齡層、廣告形式、交互作用對於該化妝品購買
意向之影響效果。(8%)
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