Question

parcu O b. Select the individuals to participate in the experiment C. Assign the treatments to the individuals within blocks d. Place the individuals into blocks O Suppose it is known that 11% of Canadian are left handed. In a random sample of 500 Canadian, what is! the approximate probability that at least 70 of them to be left handed? Select one: O a. 0.0110 ob. 0.0239 c. 0.0287 d. 0.0162 e. 0.0035 The mean and standard deviation for the charge time of a random sample of 36 iPhones were found to be 23 and 2.5 hours respectively. Assuming that the charge time was normally distributed. A 99% confidence interval for the mean charge time is:

Answer 1

Part !

Given that, p=11%=0.11 n= 500 Here we use binomial distribution function. B(x,n, p) = () * p* * (1 – p)n-* Here we have to find p(x > 70) p(x270) = 1 - p(x< 70) By using excel function “=BINOM.DIST(69,500,0.11, TRUE)” = 1-0.97822=0.02178 -0.0239

Part 2

Given, n = sample size=36, x = sample mean = 23, s= sample standard deviation=2.5 Confidence level = 99% Therefore, significance level (a)= 1-0.99 = 0.01 Degrees of freedom = n-1 =36-1 =35 t critical value at a=0.01 with df = 35 is 2.724 (for two tail) By using excel function "=T.INV.2T(0.01,35)" 99% confidence interval is, S Xt*= 2.5 = 23 + 2.724 * = 136 = (21.865, 24.135) Therefore 99% confidence interval is, 21.865 <u < 24.135