a)For the t distribution with 15 degrees of freedom, calculate
P(T < 0.691).
b)Consider the population of electric usage per month for
houses. The standard deviation of this population is 132
kilowatt-hours. What is the smallest sample size to provide a 90%
confidence interval for the population mean with a margin of error
of 34 or less? (Enter an integer number.)
c)In order to estimate the average electric usage per month, a
sample of 47 houses were selected and the...
Find the value of t for a t-distribution with 3 degrees of
freedom such that the area to the left of t equals 0.10.
Possible Answers:
A. 5.841
B. 4.541
C. -2.333
D. -1.638
Find the critical value of t for a t-distribution with 30
degrees of freedom such that the area between -t and t is 99%
A student records the repair costs for 25 randomly selected
computers from a local repair shop where he works. A sample mean of
$216.53 and standard deviation of $15.86 are subsequently computed.
Assume that the population distribution is approximately normal and
s is unknown. Determine the 98% confidence interval for the mean
repair cost for all...
How does a t-distribution differ from the
z-distribution? How do degrees of freedom (df) affect
this? What is the effect of this difference on hypothesis
testing?
- Your friend performed a two-tailed experiment in which
n = 20. He couldn’t find his t-table, but
remembered the t-critical at df = 10. He decided
to compare his t-obtained to this t-critical and
determined the results were not significant. Is this ok? Why or why
not.
What happens to a Student's t-distribution as the degrees of
freedom increase?
a.A student's t-distribution diverges from the standard normal
distribution as the degrees of freedom increases
b.A student's t-distribution converges to the standard normal
distribution as the degrees of freedom increases
Consider a random variable T that has a t-distribution with k =
16 degrees of freedom. What is P(T > 1.8)?
Group of answer choices
0.0454
0.9546
0.2499
0.4742
0.8000