Can someone help me with #8

Measurements of the sodium content in samples of two brands of chocolate bar yield the following results (in grams):

Tpy6a [65]

Answer:

98% confidence interval for the difference μX−μY = [ 0.697 , 7.303 ] .

Step-by-step explanation:

We are give the data of Measurements of the sodium content in samples of two brands of chocolate bar (in grams) below;

Brand A : 34.36, 31.26, 37.36, 28.52, 33.14, 32.74, 34.34, 34.33, 29.95

Brand B : 41.08, 38.22, 39.59, 38.82, 36.24, 37.73, 35.03, 39.22, 34.13, 34.33, 34.98, 29.64, 40.60

Also, $\mu_X$ represent the population mean for Brand B and let $\mu_Y$ represent the population mean for Brand A.

Since, we know nothing about the population standard deviation so the pivotal quantity used here for finding confidence interval is;

P.Q. = $\frac{(Xbar -Ybar) -(\mu_X-\mu_Y)}{s_p\sqrt{\frac{1}{n_1} +\frac{1}{n_2} } }$ ~ $t_n__1+n_2-2$

where, $Xbar$ = Sample mean for Brand B data = 36.9

$Ybar$ = Sample mean for Brand A data = 32.9

$n_1$ = Sample size for Brand B data = 13

$n_2$ = Sample size for Brand A data = 9

$s_p = \sqrt{\frac{(n_1-1)s_X^{2}+(n_2-1)s_Y^{2} }{n_1+n_2-2} }$ = $\sqrt{\frac{(13-1)*10.4+(9-1)*7.1 }{13+9-2} }$ = 3.013

Here, $s^{2}_X$ and $s^{2} _Y$ are sample variance of Brand B and Brand A data respectively.

So, 98% confidence interval for the difference μX−μY is given by;

P(-2.528 < $t_2_0$ < 2.528) = 0.98

P(-2.528 < $\frac{(Xbar -Ybar) -(\mu_X-\mu_Y)}{s_p\sqrt{\frac{1}{n_1} +\frac{1}{n_2} } }$ < 2.528) = 0.98

P(-2.528 * $s_p\sqrt{\frac{1}{n_1} +\frac{1}{n_2}$ < $(Xbar -Ybar) -(\mu_X-\mu_Y)$ < 2.528 * $s_p\sqrt{\frac{1}{n_1} +\frac{1}{n_2}$ ) = 0.98

P( (Xbar - Ybar) - 2.528 * $s_p\sqrt{\frac{1}{n_1} +\frac{1}{n_2}$ < $(\mu_X-\mu_Y)$ < (Xbar - Ybar) + 2.528 * $s_p\sqrt{\frac{1}{n_1} +\frac{1}{n_2}$ ) = 0.98

98% Confidence interval for μX−μY =

[ (Xbar - Ybar) - 2.528 * $s_p\sqrt{\frac{1}{n_1} +\frac{1}{n_2}$ , (Xbar - Ybar) + 2.528 * $s_p\sqrt{\frac{1}{n_1} +\frac{1}{n_2}$ ]

[ $(36.9 - 32.9)-2.528*3.013\sqrt{\frac{1}{13} +\frac{1}{9}$ , $(36.9 - 32.9)+2.528*3.013\sqrt{\frac{1}{13} +\frac{1}{9}$ ]

[ 0.697 , 7.303 ]

Therefore, 98% confidence interval for the difference μX−μY is [ 0.697 , 7.303 ] .

4 0

2 years ago

HElp fasttttttttttttttttttttttttt

Eduardwww [97]

9514 1404 393

Answer:

-0.16

Step-by-step explanation:

The 'a' value can be found by looking at the difference between the y-value of a point 1 unit from the vertex, and the y-value of the vertex.

Here, that is a negative fraction of a unit. If we assume the value is a rational number that can be accurately determined from this graph, then we can find it by looking for a point where the graph crosses a grid intersection. It looks like such grid points are (-7, 0) and (3, 0). The vertex is apparently (-2, 4), so the vertex form of the equation is ...

y = a(x +2)^2 +4

Using the point (3, 0), we have ...

0 = a(3 +2)^2 +4 . . . . . fill in the values of x and y

-4 = 25a . . . . . . . . . . subtract 4; next, divide by 25

a = -4/25 = -0.16

7 0

2 years ago

Match the type of graph with its description.

coldgirl [10]

Answer:

1) Compares data that are in categories

2) Organises data into 4 groups of equal sizes and is often used to compare two sets of data.

3) Used to see trends in data.

4) Shows changes over time.

5) Shows the frequency of data using equal intervals with no space between the bars.

Step-by-step explanation:

1) Bar graph is used to compare data that are in categories

2) Box and whisker plot is used to organise data into 4 groups of equal size.

3) Line graph is basically used to see different trends.

4) Scatter plot is used to show changes that have occurred over time

5) Histogram is used to show the frequency of data using equal intervals with no space between the bars.

4 0

2 years ago

17. What is 43 in expanded form?

masha68 [24]

Answer:

None of those that you listed are correct.

Step-by-step explanation:

All of the selections you've shown do not equal to 43. Sorry. :(

3 0

2 years ago

Read 2 more answers

8 and 5 are factors of what number?

madreJ [45]

Answer:

40

Step-by-step explanation:

8 and 5 are factors of 40. (8 x 5 = 40)

8 0

2 years ago