Question

Here is a link to a data set concerning treatment groups A and B. Before performing a t-test to determine if the two groups are different, researchers must first ascertain if the variance in the two groups is the same using an F test. Indicate whether the hypothesis below is the null or alternate hypothesis for the F test. null The variance in group A is equal to the variance in group B Calculate the F statistic for this data set and report it in the box below, rounded to two decimal places. Use the formula =(1-(f.dist(F, df1,df2,true) in Excel to calculate the P value for the F statistic, and report it in the box below. Do not use the rounded value for F when calculating the P value. Use the value in the spreadsheet that has not been rounded. Based on this p value, would you recommend using a Student's t test or a Welch's t test to determine if the two treatment groups have different means? Enter either Student's or Welch's in the box below.

57 | 70 |

66 | 27 |

65 | 15 |

40 | 86 |

64 | 49 |

11 | 16 |

34 | 57 |

61 | 29 |

26 | 73 |

45 | 71 |

30 | 98 |

43 | 46 |

64 | 88 |

19 | 22 |

14 | 53 |

14 | 59 |

11 | 94 |

34 | 18 |

68 | 68 |

39 | 62 |

Answer #1

The hypotheses are:

Enter data in excel.

By using excel function, VAR.S(data range) the variances of two groups are:

The F test statistic is:

The degrees of freedom are:

By using excel function =1-F.DIST(B25,19,19,TRUE), the p-value is 0.119.

Since p-value = 0.119 > 0.05, we fail to reject the null hypothesis and we can conclude that the variance in group A is equal to the variance in group B.

Based on this p value, you would recommend using a
**Student's t test** to determine if the two treatment
groups have different means.

Here is a link to a data set concerning three treatment groups:
A, B, & C.
A
B
C
0.0873
0.0974
0.0956
0.0571
0.0873
0.0974
0.0813
0.0662
0.1352
0.0831
0.0672
0.0817
0.0976
0.0819
0.1016
0.0817
0.0749
0.0968
0.0859
0.0649
0.1064
0.0735
0.0835
0.105
0.0659
0.0725
0.0973
0.0923
0.0703
0.1039
0.0836
0.1026
0.1045
0.0749
0.1064
0.0571
0.065
0.11
0.0814
0.1016
0.0976
0.0835
0.0968
0.0817
0.0725
0.1064
0.0859
0.0703
0.105
0.0735
0.1026
In order to perform an ANOVA on the data to...

Here is a link to the data set collected by the researchers
containing patient responses concerning the level of pain relief
they experienced over the course of the study.
Treatment
Placebo
1
1
1
1
1
1
1
1
1
1
1
2
1
2
1
2
1
2
1
2
1
3
1
3
1
3
1
3
1
3
2
4
2
4
2
4
2
4
2
4
2
4
2
4
2
5
2
5
2...

3. In a study, mosquitoes were divided into four groups of seven
mosquitoes each: infected rhesus and sporozites present (Trt 1),
infective rhesus and oocysts present (Trt 2), infective rhesus and
no infection developed (Trt 3), and noninfective (Trt 4). Distances
flown by the mosquitoes within 24 hours were recorded. The summary
data are:
?1̅. = 3.7453, ?̅2. = 4.7953, ?̅3. = 5.5472, ?̅4. = 4.8658,
∑∑??? 2 = 683.3276
Use the ANOVA F test at level = 0.10...

1) a) Find the mean, median, and standard deviation of the data
set.
b) Create an appropriate graphical display (s) and describe the
shape of the distribution. You do not have to attach the
displays.
2) Test whether the mean pulse rate of general public is greater
than 70 at 5% significance level;
Write the following:
a) Null and alternative hypotheses
b) Value of the test statistic
c) p-value
d) Conclusion. Do you have evidence to believe the mean pulse...

Here is a link to the data set collected by Dr. Hernandez. Her
research team has a data set of the weight of fishes caught from
both the contaminated lake and the pristine lake. Assume both of
these data sets have equal variance.
1.) Perform the correct statistical test and determine the P
value to test Dr. Hernandez's hypothesis. Report your answer for P
rounded to four decimal places.
Fish Weight (g)
Pristine
Contaminated
45.3
79.3
56.8
96.8
79.6
84.6...

Consider the following set of random measurements, taken from a
normally distributed population before and after a treatment was
applied.
Before Treatment
[7.38, 6.21, 7.9, 6.46, 7.56, 7.92]
After Treatment
[5.89, 6.54, 6.27, 6.52, 7.18, 6.98]
Difference
[1.49, -.33, 1.63, -.6E-1, .38, .94]
Test the null hypothesis H0:μD=0against the alternative
hypothesis HA:μD≠0.
a) What is the value of the t test statistic? Remember
to run a T test on just he difference list. Round your
response to at least 3...

Pilates is a popular set of exercises for the treatment of
individuals with lower back pain. The method has six basic
principles: centering, concentration, control, precision, flow, and
breathing. An article reported on an experiment involving 88
subjects with nonspecific low back pain. The participants were
randomly divided into two groups of equal size. The first group
received just educational materials, whereas the second group
participated in 6 weeks of Pilates exercises. The sample mean level
of pain (on a...

A college administrator is interested in knowing whether
a 3-week math mini-course affects a student's grade. Twenty
students are randomly selected and given a math test. These
students then attend the mini-course and are retested. Assume the
paired data come from a normal population for which the mean
difference is 0 Compute the value of the t-test statistic and
p-value for the paired data. At the 1% significance level,
determine whether the mini-course actually improves a student's
score.
Pre-course 68...

Problem 1: 25 patients with blisters were
randomly assigned to treatment A, treatment B and Placebo; the
number of days until the blisters heal were recorded. Are these
treatments significantly different? Use α = 5%.
Treatment A
5
6
6
7
7
8
9
10
Treatment B
7
7
8
9
9
10
10
11
Placebo
7
9
9
10
10
10
11
12
13
Sample size (n)
Median
Mean
Standard Deviation (S)
Treatment A
8
7
7.250
1.669
Treatment...

The following data are from a completely randomized design.
Treatment
Treatment
Treatment
A
B
C
32
46
33
30
45
36
30
46
35
26
48
36
32
50
40
Sample mean
30
47
36
Sample variance
6
4
6.5
At the = .05 level of significance, can we reject
the null hypothesis that the means of the three treatments are
equal?
Compute the values below (to 1 decimal, if necessary).
Sum of Squares, Treatment
Sum of Squares, Error
Mean Squares,...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 16 minutes ago

asked 26 minutes ago

asked 26 minutes ago

asked 26 minutes ago

asked 30 minutes ago

asked 44 minutes ago

asked 44 minutes ago

asked 44 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago