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What two test can be used to compare two means when the null hypothesis is rejected using the one way ANOVA f test?
Glass Houses Pty has found that the cost of fitting new sliding doors is normally distributed, with an average cost per door of R12 750, and a standard deviation of R1 095. A sample of 105 new windows is randomly selected. Assuming normal distribution: What is the probability that the average cost of fitting the doors in
the sample is less than R13 000? Interpret your answer.
Glass Houses Pty has found that the cost of fitting new sliding doors is normally distributed, with an average cost per door of R12 750, and a standard deviation of R1 095. A sample of 105 new windows is randomly selected. Assuming normal distribution: Determine the standard error for this sample.
The time taken to complete a web-based questionnaire is normally distributed, with an average time (μ) of 9 minutes and a standard deviation (σ) of 1.55 minutes. What is the probability that a randomly selected person will take: Between 8 and 8.5 minutes to complete the questionnaire? Interpret your answer.
It has been found that on average, four motorbikes go through an N1 tollgate every 20 minutes. What is the probability that
No more than 2 motorbikes will go through the tollgate in any randomly selected 20-minute period? Interpret your answer.
Use the traditional method in testing hypothesis. Developmental psychologists at a prominent California university conducted a longitudinal study investigating the effect of high levels of curiosity in early childhood on intelligence. The local population of 3-year-olds was screened via a test battery assessing curiosity. Twelve of the 3-year-olds scoring in the upper 90% of this variable were given an IQ test at age 3 and again at age 11. The following IQ scores were obtained. Student Number: 1 2 3 4 5 6 7 8 9 10 11 12 IQ (Age of 3) : 100 105 125 140 108 122 117 112 135 128 104 98 IQ (Age of 11) : 114 116 139 151 106 119 131 136 148 139 122 113 Using ∝= 0.01, two-tailed test, analyse the data and then interpret the result.
If the standard deviation of the population is 25 and the sample size is 16 then the standard deviation of sampling distribution i
