# I need a lot of help!

#### plaide

##### New Member
Hi guys. I have some questions and I will really appreciate your help! <3

1. (c) “Whenever possible, open-ended classes should be avoided.”
Give TWO reasons why we should try to avoid using open-ended classes when constructing a frequency distribution table.

2.The Body Mass Index (BMI) is a measure for human body shape based on an individual's weight and height. It is a standardised estimate of an individual’s relative body fat calculated from his or her height and weight. You took the measurement of BMI for 25 men and 25 women from the School of Business and Accountancy and calculated the following statistics in Table 5.1.

Gender Mean Variance
Women 25 36
Men 26 9
Table 5.1

The upper limit for a normal BMI for an adult is 23. You may assume that the level of significance is 5%.

(a) Based on the above information, can you say that either the group of women or group of men have above normal BMIs? Explain.

(b) Construct the hypothesis test statements for part (a). Briefly explain the construction in context.

(c) What is the critical value when testing the hypothesis?

(d) What are the limits of the acceptance region when testing the hypothesis?

(e) What is the standardised value of the sample mean for both gender?

(f) Do the sample results provide sufficient evidence to indicate that the mean BMI for an adult is above normal? You are required to explain for both genders.

3. A manager of a bank claims that 80% of their customers use the ATM machine at least once a month to withdraw cash. The average amount withdrawn by these customers is $1,000 with a standard deviation of$10.

The average amount withdrawn by the remaining 20% customers is $200 with a standard deviation of$5. The maximum number of customers using the ATM machine was found to be 200. A random sample of 36 customers was selected.

Calculate the average amount of cash per withdrawal.

Calculate the probability that the amount withdrawn by a customer is at most $845. Calculate the probability that the average amount withdrawn by a customer is at most$842.

4. (c) An advertising executive is studying television viewing habits of married men and women during prime time hours. On the basis of past viewing records, the executive has determined that during prime time, husbands are watching television 60% of the time. It has also been determined that when the husband is watching television, 40% of the time the wife is also watching. When the husband is not watching television, 30% of the time the wife is watching television. Find the probability that

(i) the wife is watching television during prime time hours.
(ii) if the wife is watching television, the husband is also watching television.

I appreciate it!