In: Math

The Federal Drug Administration wishes to determine whether the claims that Vitamin C prevents colds has any truth. In a clinical drug trial, 30 subjects were randomly assigned to either the Vitamin C group (receiving a daily supplement of the minimum daily requirement) or the placebo group (who received no supplement but did get a placebo pill). The number of self- reported colds is recorded after three years. Number of colds in 3 years: Vitamin C group: 3, 8, 6, 7, 4, 9, 2, 5, 7, 11, 10, 8, 7, 6, 7 Placebo group: 8, 8, 7, 10, 11, 4, 3, 7, 6, 8, 4, 10, 6, 8,5 The value of the numerator (either + or -) in the t test formula for Problem 3 is _____. Then what is the degrees of freedom and what is the derived t value ? Also, what can be concluded from the statistical analysis and what significance level should be reported?

(I want to compare my answers to yours, because I have different answers than what was given to me earlier on this site, and I don;t understand why...thank you.)

(a)

H0: Null Hypothesis: ( Vitamin C does not prevent colds )

HA: Alternative Hypothesis: ( Vitamin C prevents colds ) (claim)

From the given data, the following statistics are calculated:

n1 = 15

1 = 6.6667

s1 = 2.4689

n2 = 15

2 = 7

s2 = 2.3604

Pooled standard deviation (s_{P}) is given by:

So,

Test Statistic is given by:

t = (6.6667-7.0)/0.8819

= - 0.3333/0.8819

= - 0.3779

ndf = n1 + n2 - 2 = 15 + 15 - 2 = 28

Take = 0.05

One Tail - left side test

From Table, critical value of t = - 1.7011

Since calculated value of t = - 0.3779 is greater than critical value of t = - 1.7011, the difference is not significant. Fail to reject null hypothesis.

Conclusion:

The data do not support the claim that Vitamin C
prevents colds.

Answers to Questions asked:

(a) The value of the numerator (either + or -) in the t test
formula for Problem 3 = **- 0.3333**

(b) the degrees of freedom = **28**

(c) the derived t value = **- 1.7011**

(d) Conclusion: The difference is not significant. Fail to reject null hypothesis. The data do not support the claim that Vitamin C prevents colds.

(e) significance level = **0.05**

In a study to investigate whether vitamin C is an effective
treatment for colds, volunteers who caught a cold after having been
exposed to various cold viruses are assigned at random to one of
two groups. The 10 volunteers in the experimental group were given
tablets containing 1 gram of vitamin C to be taken four times a
day. The 12 volunteers in the control group were given placebo
tablets. The length of time (in days) the cold lasted for...

A study is done to see if vitamin C decreases your chance of
getting colds. In a double-blind experiment, in a random sample of
200 adults, 100 are assigned to an "experimental group" (take
vitamin C) and 100 are assigned to a "control group" (take a
placebo). The subjects in the study are the following results: In
the experimental group, 10 get cold. In the control group, 20 get
colds. Testing at a significance level a= .01, find:
a. H0,...

A statistician for a drug company wishes to
determine whether short-term memory scores are affected by the type
of medication in hyperactive children. Sixty hyperactive children
(30 boys and 30 girls) were randomly assigned to receive either
Cylert or Ritalin (two kinds of amphetamines which are CNS
stimulants). Their short-term memory was tested on a 20-point scale
(where 0 = no memory and 20 = perfect memory).
Boys Cylert: 12, 10, 13, 10, 9, 12, 13, 10, 11,
12...

The Federal Trade Commission and the Federal Food and Drug
Administration are government entities that investigate concerns
relevant to fraudulent or misleading advertisements or product
descriptions/contents. Your assignment is to research these
entities (and any governmental agencies) that do such
investigations and the outcome/consequences/sentence to a
corporation when they are involved. Give your opinion as to whether
such governmental agencies are necessary or can corporate entities
self-monitor? Give 2 specific examples. Post your findings.

Problem 1: A statistician for a drug company wishes to determine
whether short-term memory scores are affected by the type of
medication in hyperactive children. Sixty hyperactive children (30
boys and 30 girls) were randomly assigned to receive either Cylert
or Ritalin (two kinds of amphetamines which are CNS stimulants).
Their short-term memory was tested on a 20-point scale (where 0 =
no memory and 20 = perfect memory).
Boys Cylert: 12, 10, 13, 10, 9, 12, 13, 10, 11,...

A researcher wants to determine whether or not a given drug has
any effect on the score of a human subject performing a task of ESP
sensitivity. He randomly assigns his subjects to one of two groups.
900 subjects in group 1 (treatment group) receive the drug. In
contrast, 1000 subjects in group 2 (control group) receive a
placebo. For the drug group, the mean score on the ESP test was 15,
SD=4. For the no-drug group, the mean =9,...

The federal drug and administration will not approve new
pharmaceuticals products unless the developer can prove that the
product is both safe and effective remedy for specified ailments.
Do you think the safe and effective criterion would be good for
Congress to adopt for the passage of new legislation> Why or Why
not? Do you think most government action would meet this criterion?
Discuss.

The Federal Drug Administration will not approve new phar-
maceutical products unless the developer can prove that its product
is both safe and effective as a remedy for specified ailments. Do
you think the “safe and effective” criterion would be a good one
for Congress to adopt for the passage of new legislation? Why or
why not? Do you think most govern- ment action would meet this
criterion? Discuss.

The Federal Aviation Administration wants to determine the
effect of alcohol on reaction time (apparently, they really want to
know how much booze a pilot can have before flying an airplane
carrying hundreds of people). They conduct reaction time tests
(measured in milliseconds, ms) on 10 pilots before and
after consuming alcohol. Does alcohol affect reaction
time? Data are seen below.
Conduct a hypothesis test and construct a 95% C.I. for the
pre/post test difference in reaction time.
The Federal...

A university official wishes to determine whether the degree of
the instructor is related to the students’ opinion of the quality
of instruction received. A sample of students’ evaluations of
various instructors is selected, and the data in the table below
are obtained. At a = 0.10, can the officials conclude that the
degree of the instructor is related to the opinions of the students
about the instructor’s effectiveness in the class?
Degree of instructor
Opinion Rating
B.S.
M.S.
Ph.D....

ADVERTISEMENT

ADVERTISEMENT

Latest Questions

- 6.3: a factory worker pushes a 30 kg crate a distance of 4.5 m along a...
- General Systems, a computer manufacturer, announces that it will be acquiring FastWorks Software. You know the...
- . List five possible methods for deep ground improvement.
- [BI A 30kVA, 3000/1 1 0 V transfomier, the following experimental data was obtained: 0.C test:...
- 1.how can i improve my memory? 2. how is memory measured? 3. how does the brain...
- MIKE’S QUALITY REPAIR SERVICES Accounting 101 Term Project In this project, you will use the concepts...
- 1) How do you calculate the pressure produced by a pump? 2) Draw a simple regulator,...

ADVERTISEMENT