True or False: The area under the normal curve drawn with regard to the population parameters is the same as the probability that a randomly selected individual of a population has these characteristics.
A) True B) False
Q. 2A researcher wishes to estimate the proportion of people within a certain population who are HIV positive. Obtain a sample size that will ensure a margin of error of at most 4.8 percentage points for a 95 confidence interval.
Assume that it is reasonable to presume that the percentage of those sampled who are HIV positive will be between 3 and 7.
A) 49 B) 417 C) 109 D) 117
Q. 3The probability that a radish seed will germinate is 0.7. A gardener plants seeds in batches of 13. Find the standard deviation for the random variable X, the number of seeds germinating in each batch.
A) 1.587 B) 1.632 C) 1.652 D) 1.568
Q. 4What common class width was used to construct the frequency distribution?
A) 10 B) 11 C) 100 D) 9
Q. 5Compare a graph of the normal density function with mean of 0 and standard deviation of 1 with a graph of a normal density function with mean equal to 0 and standard deviation of 0.5. The graphs would
A) Have no horizontal displacement but one would be steeper that the other.
B) Have no horizontal displacement but one would be flatter than the other.
C) Have the same height but one would be shifter 4 units to the left.
D) Have the same height but one would be shifted 4 units to the right.
Q. 6The inhabitants of one town would like to have a factory closed down due to the pollution that it causes. A researcher wants to determine the proportion of children living in the vicinity of this factory that suffer from asthma.
Obtain a sample size that will ensure a margin of error of at most 0.007 for a 99 confidence interval. From a previous study, an estimate of the proportion of children suffering from asthma amongst those living in the vicinity of this factory, is 0.168.
A) 18,914 B) 132 C) 10,958 D) 17,023
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