Stats final
More evidence against H0 is indicated by
smaller p-values
x is a normally distributed random variable with a mean of 12 and a standard deviation of 3. The probability that x equals 19.62 is
0.000
For a standard normal distribution, the probability of z 0 is
0.5
If a categorical independent variable contains two categories, then _________ dummy variable(s) will be needed to uniquely represent these categories.
1
If the mean of a normal distribution is negative,
None of these alternatives is correct.
In regression analysis, which of the following assumptions is not true about the error term ε?
The expected value of the error is one
What type of error occurs if you fail to reject H0 when, in fact, it is not true?
Type II
A normal distribution with a mean of 0 and a standard deviation of 1 is called
a standard normal distribution.
A Type I error is committed when
a true null hypothesis is rejected
In interval estimation, as the sample size becomes larger, the interval estimate
becomes narrower
As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution
becomes smaller
The proportion of the variation in the dependent variable y that is explained by the estimated regression equation is measured by the
coefficient of determination
To compute the minimum sample size for an interval estimate of µ, we must first determine all of the following except
degrees of freedom.
The center of a normal curve is
is the mean of the distribution.
The value added to and subtracted from a point estimate in order to develop an interval estimate of population parameter is known as the
margin of error
If the null hypothesis is rejected at the 5% level of significance, it
may be rejected or not rejected at the 1% level
In a standard normal distribution, the
mean is 0 and the standard deviation is 1.
The p-value
must be a number between zero and one
When constructing a confidence interval for the population mean using the standard deviation of the sample, the degrees of freedom for the t distribution equals
n - 1
Convenience sampling is an example of
nonprobabilistic sampling.
A sample of 92 observations is taken from an infinite population. The sampling distribution of is approximately
normal because of the central limit theorem.
A sample of 200 elements from a population with a known standard deviation is selected. For an interval estimation of μ, the proper distribution to use is the
normal distribution
The number of degrees of freedom associated with the chi-square distribution in a test of independence is
number of rows minus 1 times number of columns minus 1.
Which of the following is(are) point estimator(s)?
s
The required condition for using an ANOVA procedure on data from several populations is that the
sampled populations have equal variances
In interval estimation, the t distribution is applicable only when
the sample standard deviation is used to estimate the population standard deviation.
For a normal distribution, a negative value of z indicates
the z is to the left of the mean.
The ANOVA procedure is a statistical approach for determining whether or not the means of
three or more populations are equal.
If we change a 95% confidence interval estimate to a 99% confidence interval estimate, we can expect the
width of the confidence interval to increase.