Deck 12: Comparing Several Means

Question 1

The bigger the margin of error,the smaller the confidence interval.

Answer 1

False

Question 2

A student draws a playing card from a standard pack of 52.What is the probability that the student draws a king or a heart?

A)1/4
B)4/13
C)7/52
D)13/52

Answer 2

B

Question 3

The standard error is a measure of variability.

Answer 3

True

Question 4

A sample consists of four observations,scored as 1,3,5,7.What is the standard deviation?

A)2.55
B)2.58
C)3.02
D)3.99

Question 5

A sample survey is an example of an observational study.

Question 6

The centre of a confidence interval is a sample statistic.

Question 7

The standard error is a measure of central tendency.

Question 8

A sample mean is an example of a point estimate.

Question 9

A population mean is an example of a point estimate.

Question 10

The average height of a randomly selected group of adult males could be a discrete random variable.

Question 11

900 secondary school students are selected randomly from across the country because they have achieved 10 GCSEs at grade A -C.There is a standard deviation of 0.4.Assuming a 95% confidence rate,what is the margin of error?

A)0.011
B)0.025
C)0.178
D)0.555

Question 12

The confidence interval is a type of point estimate.

Question 13

The standard error is calculated only from sample attributes.

Question 14

The annual number of UK lottery winners could be a discrete random variable.

Question 15

The best method for investigating casual relationships is an observational study.

Question 16

An observational study requires fewer resources than an experiment.

Question 17

The standard deviation requires knowledge of at least one population parameter.

Question 18

A sample survey is an example of an experimental study.

Question 19

The standard deviation is calculated only from sample attributes.

Question 20

The number of twentieth-century US presidential elections is not a discrete random variable.Why not?

A)There is no integer.
B)The integer does not vary and is not random.
C)It results from random process.
D)Another reason.

Question 21

Random sampling is a good way to protect against undercoverage bias.

Question 22

Random sampling is a good way to reduce response bias.

Question 23

A simple random sample was conducted to select 1600 of 100,000 subscribers to an educational research journal.The selected participants were asked whether the journal should increase its base of research coverage to include more social science articles.40% of participants requested an expansion in coverage.What is the 99% confidence interval for the proportion of subscribers who would like a wider research coverage?

A)[.30,.50]
B)[.32,.48]
C)[.33,.44]
D)[.37,.43]

Question 24

150 sixth-form students are sampled (a simple random sample)from 3000 in sixth-form colleges across the West Midlands.From the sampled students,an average IQ of 115 is determined,with a standard deviation of 10.What is the 99% confidence interval?

A)115 ± 0.01
B)115 ± 1.22
C)115 ± 2.10
D)115 ± 3.22