What is the standard error of the sample mean?
Q. 2A null hypothesis is that the probability is 0.7 that a new drug will provide relief in a randomly selected patient. The alternative is that the probability of relief is greater than 0.7 . Suppose the treatment is used on 500 patients and there are 380 successes. How would a p-value be calculated in this situation?
a. Find the chance of 380 or more successes, calculated assuming the true success rate is greater than 0.7.
b. Find the chance of 380 or more successes, calculated assuming the true success rate is 0.7.
c. Find the chance of fewer than 380 successes, calculated assuming the true success rate is greater than 0.7.
d. Find the chance of fewer than 380 successes, calculated assuming true success rate is 0.7.
Q. 3Grade school students, especially the ones in higher grades, tend to spend a lot of time on the computer already. The average amount of time 4th grade boys spend on the computer is 5 hours per week, with a standard deviation of 1 hour. For 5th grade boys the average increases to 7 hours per week with a standard deviation of 1.5 hours. Random sample of 20 4th grade students and 25 5th grade students are to be selected. What is the probability that the difference between the sample means is greater than 1 hour?
Q. 4Consider testing the alternative hypothesis that the proportion of adult Canadians opposed to same-sex marriage in Canada is less than 0.5 . The test was conducted based on a poll of n = 1003 adults and it had a p-value of 0.102 . Which of the following describes the probability represented by the p-value for this test?
a. It is the probability that fewer than half of all adults in Canada that year were opposed to same-sex marriage.
b. It is the probability that more than half of all adult Canadians that year were opposed to same-sex marriage.
c. It is the probability that a sample of 1003 adults in Canada that year would result in 48 or fewer saying they are opposed to same-sex marriage, given that a majority (over 50) of Canadian adults actually were opposed that year.
d. It is the probability that a sample of 1003 adults in Canada that year would result in 48 or fewer saying they are opposed to same-sex marriage, given that 50 of Canadian adults actually were opposed that year.
Q. 5Grade school students, especially the ones in higher grades, tend to spend a lot of time on the computer already. The average amount of time 4th grade boys spend on the computer is 5 hours per week, with a standard deviation of 1 hour. For 5th grade boys the average increases to 7 hours per week with a standard deviation of 1.5 hours. Random sample of 20 4th grade students and 25 5th grade students are to be selected. What is the standard deviation of the sampling distribution of the difference in sample means?
Q. 6About 90 of the general population is right-handed. A researcher speculates that artists are less likely to be right-handed than the general population. In a random sample of 100 artists, 83 are right-handed. Which of the following best describes the p-value for this situation?
a. The probability that the population proportion of artists who are right-handed is 0.90.
b. The probability that the population proportion of artists who are right-handed is 0.83.
c. The probability the sample proportion would be as small as 0.83, or even smaller, if the population proportion of artists who are right-handed is actually 0.90.
d. The probability that the population proportion of artists who are right-handed is less than 0.90, given that the sample proportion is 0.83.
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