Given the following information about a hypothesis test of the difference between two means based on independent random samples, what is the standard deviation of the difference between the two means? assume that the samples are obtained from normally distributed populations having equal variances. h0: ? a = ? b, and h1: ? a > ? b x ¯ 1 = 12, x ¯ 2 = 9, s1= 5, s2 = 3, n1 =13, n2 =10.a. 1.792b. 1.679c. 2.823d. 3.210e. 1.478

B. 1.679

Step-by-step explanation:

The standard deviation for the difference between two mean is given by :-

, where = sample size from population 1.

= sample size from population 2.

= sample mean differnce.

= sample standard deviations .

Given :

Then, the standard deviation of the difference between the two means will be  :

The nearest option : B. 1.679

Hence, the  standard deviation of the difference between the two means = 1.679

answer: c

because if you look at the chart you can see a pattern and compare it to the question he simplify out your

but i think the formula is f(x)=6x

the total estimated nappy use.=10,500,000

step-by-step explanation:

given that on an average the average baby uses 3528 napkins.

in a particular year 2014, the number of births were 299697 in new south wales.

rounding off the number of births to the nearest hundred thousand we have

no of birtsh = 300000

also rounding off the average usage to nearst thousand we get

average use of a baby = 3500

hence total number of nappy estimated to be used = 3500x300000

= 10,500,000

answer is 10,500,000 nappies