Good day :)

I hope you are doing well.

I am currently studying for statistics, but I am struggling with these questions.

I would greatly appreciate it if you could provide your assistance and guidance by explaining these specific questions to me by showing calculations etc.

With the questions that are about hypothesis testing, if possible, could you please show me the whole process of hypothesis testing with each question.

Please know that I would like explanations on the specific questions that are in the photo.

Your assistance is greatly appreciated!

I look forward to your reply.

Kind regards.

Question 23 points Save Answer A small opinion poll among 200 Johannesburg and 100 Durban citizens indicated that 48% and 52% respectively, would buy an electrical vehicle if the price is less than R16 000. Is there a difference between the numbers of citizens in Durban that would buy an electrical vehicle than in Johannesburg? Test at a significance level of 5% if the populations are independent and normally distributed. Give the null and alternative hypothesis. O HOP1 = Pz ; HalPi Pz O HOP, SPz ; He:P1 = Pz Question 24 1 points Save Answer Fifty two of a test panel of 175 consumers say that they would buy cereal A if it is presented on the market and 35 of another test panel of 150 consumers say that they would buy cereal B. Test the null hypothesis that the cereals on the market would be equally popular. Use a 5% significance level. Calculate the test statistic O 0.0974 O 1.169 O 1.2949 O 1.2952 Question 25 1 points Save Answer The IQ's of 51 students are tested and it is found that the average IQ is 108 with a standard deviation of 10. Test Ho: ? = 81 vs H.:? # 81 using a 5% significance level. Calculate the test statistic and outcome of the test O x? = 61.7284 Reject Ha O x2 = 0.7621 Reject Ha O x2 = 62.9630 Reject Ho x2 = 55.5556 Reject Ho Question 26 1 points Save Answer The weight of certain population of young females is approximately normally distributed with the mean of 66 kg and a standard deviation of 7.5 kg, If an individual is selected at random from this population, find the probability that she will weigh between 52.5 and 72.5 kg O 0.9641 O 0.8078 O 0.7719 O 0.2281 0.1563 None eof the above Question 27 1 points Save Answer In a particular hospital, 60% of the staff is male and 40% female. In a random sample of 50 staff members, what is the probability that more than half will be female? O 0.9251 O 0.9032 O 0.3228 O 0.9441 O 0.0749 O 0.0559 Question 28 1 points Save Answer Sample of 15 test-tubes tested for number of times they cracked gave the sample mean of 1230 with a standard deviation of 270. Construct 99% confidence interval mean time a test tube can be cracked, give the upper limit of the interval. Assume normal distribution. 1379.5359 1022.4623 1435.4463 O 1437.5377 1080.4641 1024.5537 Question 29 1 points Save Answer The ages of competitors in a grandmaster chess tournament is under dispute. The National Chess League (NCL) claims that the average age of a grandmaster is 55. A random sample of 50 competitors at a recent tournament resulted in a mean of 59,18 and a variance of 168,60. Test at a 1% level of significance whether the NCL's claim is true. The critical value is O -2.576 O 1.282 O = 2.326 1.645 O +2.576 Question 30 1 points Save Answer If the mean and standard deviation of serum iron values for healthy men are 120 and 15 micrograms per 100 ml, what is the probability that a random sample of 50 healthy men will yield a mean more than 125 micrograms per 100 ml? O 0.9906 O 0.6293 O 0.3707 O 0.9909 O 0.0091 O None of the above