澳洲代写主要为商业统计相关的限时测试

问题1.对于数值数据,间隔的测量尺度与测量值之间有什么区别
测量比例的比例?给出一个数字数据的示例,其测量比例为比率。

问题2.下表显示了每日相对频率的频率分布
新南威尔士州11月的气温。温度为2的概率是多少
连续天数超过20o
C?假设每天的温度是独立的。

温度相对频率

问题3:有50个彩色球(10个红色球,15个黄色球,20个紫色球,5个蓝绿色球)
在盒子里。如果我们要计算随机出现3个黄色小球的概率
选择5个球,可以使用二项式分布。解释为什么/为什么不。

问题4.投资者可以投资两只股票。两种股票的预期收益率都相同。
股票A和股票B。不用任何数学,就解释为什么她想成为一个规避风险的投资者
选择收益在四分位数之间较小的股票。

了解初婚年龄(不超过25岁,
25岁和35岁以上,35岁以上的女性)及其受教育程度(小学,中学,大专)。基于
在以下不完整的列联表中,回答问题5和问题6。

小学中学高等教育总计
小于25 30 5 60
25至35 10 20 15之间
小于35 15 70
总计50175

问题5.假设一个37岁的女人是第一次结婚。她有大专生的几率是多少
教育?

问题6:用于检验初婚年龄和受教育程度是否为𝜒𝜒2的统计量
独立等于37.8263。在5%的水平下,临界值是多少,测试结果是什么?

问题7.泊松分布具有一种有时称为“泊松到达”的属性
查看指数等待时间”。这是什么意思?

问题8.已知经过回旋处的车辆数量遵循泊松(Poisson)
分配。平均在一个非高峰时段,有20辆车经过回旋处;然而
平均而言,在高峰时段,通过回旋处的车辆数量增加了一倍。是什么
在高峰时段,一辆车经过回旋处后,一辆车之间需要等待的概率
分钟和三分钟才能看到下一辆车?

Question 1. For numerical data, what is the difference between the measurement scale of interval and the
measurement scale of ratio? Give an example of numerical data whose measurement scale is ratio.

Question 2. The following table shows the frequency distribution in terms of relative frequency of daily
temperatures in November in New South Wales. What is the probability that the temperature of two
consecutive days exceeds 20o
C? Assume daily temperatures are independent.

Temperature Relative frequency

Question 3. There are 50 coloured balls (10 red balls, 15 yellow balls, 20 purple balls, 5 blue green balls)
in a box. If we would like compute the probability that there are exactly 3 yellow balls out of a random
selection of 5 balls, can we use the binomial distribution. Explain why / why not.

Question 4. There are two stocks an investor can invest in. The expected rate of return is the same for both
Stock A and Stock B. Without using any maths, explain why for a risk-averse investor she would like to
choose a stock whose returns have a smaller inter-quartile range.

It is of interest to know the dependence structure between age of first marriage (younger than 25, between
25 and 35, older than 35) of females and their education attainment (Primary, Secondary, Tertiary). Based
on the following incomplete contingency table, answer Question 5 and Question 6.

Primary school Secondary school Tertiary school Total
Younger than 25 30 5 60
Between 25 and 35 10 20 15
Older than 35 15 70
Total 50 175

Question 5. Suppose a woman aged 37 just got married the first time. What is the probability she has tertiary
education?

Question 6. The 𝜒𝜒2 statistic used to test whether or not age of first marriage and education attainment are
independent equals 37.8263. At the 5% level, what is the critical value and what is the test result?

Question 7. The Poisson distribution has one property that is sometimes referred to as “Poisson arrivals
see exponential waiting time”. What does it mean?

Question 8. It is known that the number of vehicles passing through a roundabout follows a Poisson
distribution. On average during a single off-peak hour, 20 vehicles pass through the roundabout; whereas
on average during a peak hour, number of vehicles that pass through the roundabout doubles. What is the
probability that during a peak hour, after one vehicle passes the roundabout one needs to wait between one
minute and three minutes to see the next vehicle?