Search & Filtering
A quality-control manager at an amusement park feels that the amount of time that people spend waiting in line to ride the roller coaster is too long. To determine if a new loading and unloading procedure is effective in reducing the wait time, she measures the amount of time (in minutes) people are waiting in line for seven days. To make a reasonable comparison, she chooses times when weather conditions are similar.
Mon. Tues. Wed. Thurs. Fri. Sat. Sun
2 pm. 2 pm. 2 pm. 2 pm. 2 pm. 4 pm. 12 noon
Wait time before x1 12. 26. 20. 38. 57. 82 57
Wait time before x2. 11. 28. 19. 36. 59. 75. 55
Is the new loading and unloading procedure effective in reducing the wait time at the α = 0.05 level of significance?
A fair spinner has 9 equal sections: 4 red, 3 blue and 2 green.
It is spun twice.
What is the probability of not getting two consecutive blues?
Academicians was surveyed of their loyalty to the university. They're asked “If given an offer by other university equivalent or slightly better than present position, would you remain or not?Table 4 represents the responses of the 200 academicians which were cross-classified with their length of service.
Table 4: Loyalty of Academicians & Length of Service.
Length of Service Total
Loyalty Less than1 yr, 1-5 yr, 6-10 yr, More than 10 yr
Remain 10 30 5 75 120
Not remain 25 15 10 30 80
a)represent the information in Table 4 as a tree diagram.
b)What's the probability of randomly who is loyal and who has more than 10 yr service?
c)What's the probability of who would not remain and has less than 1-yr of service?
d)What's the probability of who would remain, given that he or she has 1-5 yr of service?
e)What's the probability of who would not remain, given that he or she 6-10 yr of service?
f)What's the probability of an academic with more than 10 yr of service or one who would not remain?
(1)The data in Table 1 shows the age of 40 randomly selected university learners.
Table 1: Age of university Learners
24 39 33 30 33 34 25 27
36 32 44 49 29 35 34 31
38 43 35 31 36 38 39 44
36 29 28 35 39 37 42 48
40 26 45 41 41 28 24 39
Given that the lower limit of the first class interval is 23 and the class width is 4.
i. Prepare a frequency and relative frequencydistribution of the data.
ii. Represent the data by using a histogram.
iii. Construct a cumulative frequency polygon of the type “ < ” .
iv. Use your graph in a)iii to estimate first quartile, median and third quartile.b) The data in Table 2 represents the prices of Seabass (RM/kg) sold at two different wet markets for 9 consecutive days.
Table 2: Price of Seabass (RM/kg)
Wet Market A
23 23 24 23 24 23 22 22 23
Wet Market B
20 20 21 22 22 23 21 21 23
For each type of market,
i. calculate the mean and standard deviation.
ii. compare their data spread using the coefficient of variation.
Snowfalls occur randomly and independently over the course of winter in a Minesota city. The average is one snowfall every 3 days.
a. What is the probability of five snowfalls in 2 weeks?
b. Find the probability of a snowfall today.
TRUE OR FALSE
The researcher can only make a claim on the alternative hypothesis in the traditional method of hypothesis testing.
. Fifty percent of Americans believed the country was in a recession, even though technically the economy had not shown two straight quarters of negative growth (BusinessWeek, July 30, 2001). For a sample of 20 Americans, make the following calculations. a. Compute the probability that exactly 12 people believed the country was in a recession. b. Compute the probability that no more than five people believed the country was in a recession. c. How many people would you expect to say the country was in a recession? d. Compute the variance and standard deviation of the number of people who believed the country was in a recession.
The internet provider claims that their router gives a speed of 25 Mbps with a standard deviation of 4.8 Mbps. The computer engineer wants to check whether the speed is different than what the provider claims. For this study, the engineer collects the speed of 40 routers and found that the average speed is 23.2 Mbps for those 40 routers. Plot the acceptance and rejection region for a two-sided test to test the claim of engineer with 90% confidence.
A jar contains 5 red marbles numbered 1 to 5 and 8 blue marbles numbered 1 to 8 . A marble is drawn at random from the jar. Find the probability the marble is
a. Even-numbered given that the marble is red.
b. Red given that the marble is even-numbered.
Find the class boundaries midpoints and widths for the given class 43-47
