An education researcher wishes to assess the effectiveness of three different methods for teaching young children to read. The 380 children participating in the study are divided into three groups. The study runs for six months.
The children in the first group are taught using method A, the children in the second group are taught using method B, and the children in the third group are taught using method C. At the end of the six months, the reading ability of the children in the different groups is assessed. Why might randomization be used when dividing the children into three groups?
Q. 2The probability that a football game will go into overtime is 13. What is the probability that two of three football games will go to into overtime?
A) 0.0169 B) 0.044 C) 0.13 D) 0.295
Q. 3In a clinical test with 2086 subjects, 1477 showed improvement from the treatment. Find the margin of error for the 95 confidence interval used to estimate the population proportion.
A) 0.0218 B) 0.0195 C) 0.0166 D) 0.0263
Q. 4According to insurance records a car with a certain protection system will be recovered 86 of the time. Find the probability that 4 of 7 stolen cars will be recovered.
A) 0.14 B) 0.053 C) 0.86 D) 0.571
Q. 5Explain the difference between an observational study and a designed experiment.
What will be an ideal response?
Q. 6In a survey of 6700 T.V. viewers, 3350 said they watch network news programs. Find the margin of error for the 99 confidence interval used to estimate the population proportion.
A) 0.0120 B) 0.0138 C) 0.0158 D) 0.00900
Q. 7The probability that an individual has 20-20 vision is 0.15. In a class of 99 students, what is the probability of finding five people with 20-20 vision?
A) 0.051 B) 0.001 C) 0.15 D) 0.000
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