Question

Please help, thank you!!

Randomly selected deaths of motorcycle riders in a region of the northern hemisphere are summarized in the accompanying table. Use a 0.05 significance level to test the claim that such fatalities occur with equal frequency in the different months. How might the results be explained? Month Jan. Feb. March April May June Number 9 11 13 18 19 26 Month July Aug. Sept. Oct. Nov. Dec. Number 22 29 26 15 11 6 Determine the null and alternative hypotheses. Ho: Fatalities occur with the same frequency in the different months of the year H: At least one month has a different frequency of fatalities than the other months. Calculate the test statistic, 2 (Round to three decimal places as needed.) Calculate the P-value. P.value (Round to three decimal places as needed.) What is the conclusion for this hypothesis test? Because the P-value is 5 6t 6 62 6 64 the significance level, Ho. There suficient evidence to warrant rejection of the claim that motorcycle fatalities occur with equal frequency in the66 diffarent monthe Click to select your answer(s) 67 In a clinical trial of a certain drug, 17 subjects experience headaches among the 223 subjects treated with the drug. Construct a 99% (Wald) confidence interval estimate for the proportion of treated subjects who experience headaches, completing parts (a) through (d) below a. Find the best point estimate of the population proportion. 0.076 (Type an integer or a decimal rounded to three decimal places as needed.) b. Identify the value of the margin of error E. 0.046 (Type an integer or a decimal rounded to three decimal places as needed.) c. Construct the confidence interval. eps Round to three decimal places as needed.) d. Write a statement that correctly interprets the confidence interval. Select the correct choice below and fill in the answer box to complete your choice. (Type an integer or a decimal. Do not round.) ○ A. There is a □% chance that the true value of the population proportion of subjects treated with the drug who experience headaches will fall between the confidence interval's lower and upper limits. B. We have 199% confidence that the true value of the sample proportion of subjects treated with the drm, whn ρχηerience headaches actuallv is hetwAen the nfidence interval's lower and inner limits Click to select your answer(s). iniversal

Answer 1

Following table shows the calculations:

	O	E=205/12	(O-E)^2/E
	9	17.083	3.824555933
	11	17.083	2.166065035
	13	17.083	0.975875959
	18	17.083	0.049223731
	19	17.083	0.215119651
	26	17.083	4.654503834
	22	17.083	1.415260142
	29	17.083	8.313228883
	26	17.083	4.654503834
	15	17.083	0.253988702
	11	17.083	2.166065035
	6	17.083	7.190358192
Total	205	204.996	35.87874893

Following is the test statistics:

(O-E35.879

The degree of freedom: df=n-1=12-1=11

The p-value using excel function "=CHIDIST(35.879,11)" is: 0.000

Since p-value is less than 0.05 so we reject the null hypothesis.

There is sufficient evidence....

----------------------------

Here we have x -17, n-223, /p--0.0762 Level of significance α=0.01 : Critical value: 2.576 The standard deviation is: POP σ,-11- _-sqrt((0.0762 *(1-0.0762))/223) n =00178 The requried confidence interval is: ptŽe.Ơp -0.0762 -0.0762 0.0459 (2.576*0.0178) =(0.03,0.122) Excel function for critical value: NORMSINV(1-(0.01/2)) Hence, the required confidence interval is (0.03,0.122)

(c)

The confidence interval is 0.030 <p < 0122

(d)

Correct option is B.