Question 18 plz help <3

The degenerative disease osteoarthritis most frequently affects weight-bearing joints such as the knee. Two random samples from

Vinvika [58]

Answer:

$t=\frac{(810-770)-0}{\sqrt{\frac{67^2}{13}+\frac{56^2}{19}}}}=1.771$

$df=n_1 +n_2 -2=13+19-2=30$

Since is a right tailed test the p value would be:

$p_v =P(t_{30}>1.771)=0.0434$

Comparing the p value with the significance level $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the mean for group 1 is significantly higher than the mean for the group 2

Step-by-step explanation:

Data given

$\bar X_{1}=810$ represent the mean for sample 1

$\bar X_{2}=770$ represent the mean for sample 2

$s_{1}=67$ represent the sample standard deviation for 1

$s_{2}=56$ represent the sample standard deviation for 2

$n_{1}=13$ sample size for the group 2

$n_{2}=19$ sample size for the group 2

$\alpha=0.05$ Significance level provided

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the mean for category 1 is higher than the mean for category 2, the system of hypothesis would be:

Null hypothesis: $\mu_{1}-\mu_{2}\leq 0$

Alternative hypothesis: $\mu_{1} - \mu_{2}> 0$

We don't have the population standard deviation's, so for this case is better apply a t test to compare means, and the statistic is given by:

$t=\frac{(\bar X_{1}-\bar X_{2})-\Delta}{\sqrt{\frac{\sigma^2_{1}}{n_{1}}+\frac{\sigma^2_{2}}{n_{2}}}}$ (1)

And the degrees of freedom are given by $df=n_1 +n_2 -2=13+19-2=30$

t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

With the info given we can replace in formula (1) like this:

$t=\frac{(810-770)-0}{\sqrt{\frac{67^2}{13}+\frac{56^2}{19}}}}=1.771$

P value

Since is a right tailed test the p value would be:

$p_v =P(t_{30}>1.771)=0.0434$

Comparing the p value with the significance level $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the mean for group 1 is significantly higher than the mean for the group 2

4 0

3 years ago

What is the answer for this problem?

Y_Kistochka [10]

This is a problem involving the subtraction of two functions f(x) and g(x):

<span>if f(x)=3x-1 and g(x)=x+2, find (f-g)(x). In other words, find:

</span><span> f(x) = 3x-1
-{g(x) -(x+2)
-----------------
f(x) - g(x) = 3x - 1 - x - 2 = 2x - 3 (answer)</span>

4 0

3 years ago

How do you do this?

Nat2105 [25]

U just need to add row by row
I'll do the first 1: 1+1=2
1+2=3
1+3=4
1+4=5
1+5=6

3 0

3 years ago

Read 2 more answers

An item is regularly priced at $81. It is on sale for 45% off the regular price. Find the sale price.

Triss [41]

Answer:

44.55

Step-by-step explanation:

Internet said this: "Thus, a product that normally costs $ 81 with a 45 percent discount will cost you $ 44.55, and you saved $ 36.45. You can also calculate how much you save by simply moving the period in 45.00 percent two spaces to the left, and then multiply the result by $ 81 as follows: $ 81 x. 45 = $ 36.45 savings."

Hope this helps∞<3

Let me know if it right or wrong!

3 0

3 years ago

Read 2 more answers

I rlly don’t understand due today please help!

tatuchka [14]

Answer:

a) 2x+4

b)x=8

Step-by-step explanation:

a) x+x+4 =2x +4

b) 2x+4= 20

2x = 16

x=8

Jay bought 8 packets of Chips

c) Jay: 8 x 60

=£4,80

Lauren : 12 × 60

= £7,2

7 0

2 years ago