# 0.2 Practice tests (1-4) and final exams  (Page 18/36)

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32 . Explain in words what it means that a screening test for TB has an α level of 0.10. The null hypothesis is that the patient does not have TB.

33 . Explain in words what it means that a screening test for TB has a β level of 0.20. The null hypothesis is that the patient does not have TB.

34 . Explain in words what it means that a screening test for TB has a power of 0.80.

## 9.3: distribution needed for hypothesis testing

35 . If you are conducting a hypothesis test of a single population mean, and you do not know the population variance, what test will you use if the sample size is 10 and the population is normal?

36 . If you are conducting a hypothesis test of a single population mean, and you know the population variance, what test will you use?

37 . If you are conducting a hypothesis test of a single population proportion, with np and nq greater than or equal to five, what test will you use, and with what parameters?

38 . Published information indicates that, on average, college students spend less than 20 hours studying per week. You draw a sample of 25 students from your college, and find the sample mean to be 18.5 hours, with a standard deviation of 1.5 hours. What distribution will you use to test whether study habits at your college are the same as the national average, and why?

39 . A published study says that 95 percent of American children are vaccinated against measles, with a standard deviation of 1.5 percent. You draw a sample of 100 children from your community and check their vaccination records, to see if the vaccination rate in your community is the same as the national average. What distribution will you use for this test, and why?

## 9.4: rare events, the sample, decision, and conclusion

40 . You are conducting a study with an α level of 0.05. If you get a result with a p-value of 0.07, what will be your decision?

41 . You are conducting a study with α = 0.01. If you get a result with a p -value of 0.006, what will be your decision?

Use the following information to answer the next five exercises. According to the World Health Organization, the average height of a one-year-old child is 29”. You believe children with a particular disease are smaller than average, so you draw a sample of 20 children with this disease and find a mean height of 27.5” and a sample standard deviation of 1.5”.

42 . What are the null and alternative hypotheses for this study?

43 . What distribution will you use to test your hypothesis, and why?

44 . What is the test statistic and the p -value?

46 . Suppose the mean for your sample was 25.0. Redo the calculations and describe what your decision would be.

## 9.5: additional information and full hypothesis test examples

47 . You conduct a study using α = 0.05. What is the level of significance for this study?

48 . You conduct a study, based on a sample drawn from a normally distributed population with a known variance, with the following hypotheses:
H 0 : μ = 35.5
H a : μ ≠ 35.5
Will you conduct a one-tailed or two-tailed test?

pls I need understand this statistics very will is giving me problem
Sixty-four third year high school students were given a standardized reading comprehension test. The mean and standard deviation obtained were 52.27 and 8.24, respectively. Is the mean significantly different from the population mean of 50? Use the 5% level of significance.
No
Ariel
how do I find the modal class
look for the highest occuring number in the class
Kusi
the probability of an event occuring is defined as?
The probability of an even occurring is expected event÷ event being cancelled or event occurring / event not occurring
Gokuna
what is simple bar chat
Simple Bar Chart is a Diagram which shows the data values in form of horizontal bars. It shows categories along y-axis and values along x-axis. The x-axis displays above the bars and y-axis displays on left of the bars with the bars extending to the right side according to their values.
statistics is percentage only
the first word is chance for that we use percentages
it is not at all that statistics is a percentage only
Shambhavi
I need more examples
how to calculate sample needed
mole of sample/mole ratio or Va Vb
Gokuna
how to I solve for arithmetic mean
Yeah. for you to say.
James
yes
niharu
how do I solve for arithmetic mean
niharu
add all the data and divide by the number of data sets. For example, if test scores were 70, 60, 70, 80 the total is 280 and the total data sets referred to as N is 4. Therfore the mean or arthritmatic average is 70. I hope this helps.
Jim
*Tan A - Tan B = sin(A-B)/CosA CosB ... *2sinQ/Cos 3Q = tan 3Q - tan Q
standard error of sample
what is subjective probability
how to calculate the Steadman rank correlation
David
what is sampling? i want to know about the definition of sampling.
what is sample...?
In terms of Statistics or Research , It is a subset of population for measurement.
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