Can someone please tutor me in math

Tensile-strength tests were carried out on two different grades of wire rod. Grade 1 has 10 observations yielding a sample mean

earnstyle [38]

Answer:

$t=\frac{(1085 -1034)-(0)}{57.646\sqrt{\frac{1}{10}+\frac{1}{15}}}=2.167$

$p_v =2*P(t_{23}$

We see that the p value is lower than the significance level provided of 0.05 so then we have enough evidence to conclude that the true means are different at 5% of significance.

Step-by-step explanation:

Data given

$n_1 =10$ represent the sample size for group 1

$n_2 =15$ represent the sample size for group 2

$\bar X_1 =1085$ represent the sample mean for the group 1

$\bar X_2 =1034$ represent the sample mean for the group 2

$s_1=52$ represent the sample standard deviation for group 1

$s_2=61$ represent the sample standard deviation for group 2

We are assuming that the two samples are normally distributed with equal variances and that means:

$\sigma^2_1 =\sigma^2_2 =\sigma^2$

System of hypothesis

Null hypothesis: $\mu_1 = \mu_2$

Alternative hypothesis: $\mu_1 \neq \mu_2$

The statistic is given by:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{S_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2}}}$

The degrees of freedom are given by:

$n_1+n_2 -2$

And the pooled variance is:

$S^2_p =\frac{(n_1-1)S^2_1 +(n_2 -1)S^2_2}{n_1 +n_2 -2}$

Replacing we got:

$S^2_p =\frac{(10-1)(52)^2 +(15 -1)(61)^2}{10 +15 -2}=3323.043$

And the deviation would be:

$S_p=57.646$

The degrees of freedom are:

$df=10+15-2=23$

The statistic would be:

$t=\frac{(1085 -1034)-(0)}{57.646\sqrt{\frac{1}{10}+\frac{1}{15}}}=2.167$

The p value would be

$p_v =2*P(t_{23}$

We see that the p value is lower than the significance level provided of 0.05 so then we have enough evidence to conclude that the true means are different at 5% of significance.

6 0

3 years ago

Jeremy is writing down a sequence of integers. He writes 1 as his first number. Then, he

Pachacha [2.7K]

Answer:

<em>4 is the unit's digit of the 20th number.</em>

Step-by-step explanation:

Let us try to find out a pattern for the unit's digit of the terms.

1st term is 1, so unit's digit of 1st term is 1.

2nd term $1^{2} + 3 = 4$ so unit's digit is 4.

3rd term $4^{2} + 3 = 19$ so unit's digit is 9.

4th term $19^{2} + 3 = 364$ so unit's digit is 4.

5th term's unit digit: Square of unit's digit of 4th term + 3

$4^{2} + 3 = 19$ i.e. 9.

:

We can see that the pattern is

3rd, 5th, 7th ...... terms have 9 as the unit's digit.

2nd, 4th, 6th.... terms have 4 as the unit's digit.

So, 20th term will have 4 as the unit's digit.

4 0

3 years ago

Choose the correct way to revise the following run-on sentence.

Mila [183]

C SINCE IT IS A RUNOFF SENTENCE THERE SHOULD BE NO other marks

7 0

3 years ago

Geometry. I'm really struggling with this.

julia-pushkina [17]

Answer:

The measure of Angle G is 62.5°.

Step-by-step explanation:

Given:

Δ EFG is an Isosceles Triangle.

EG = EF

m∠ E = 55°

To Find:

m∠ G = ?

Solution:

Δ EFG is an Isosceles Triangle. ........Given

EG = EF ..............Given

∠ G = ∠ F = x (say) ..................Isosceles triangle property

Now in Δ EFG we have

∠ E + ∠ G + ∠ F = 180° .......... Angle sum property of triangle

On substituting the values we get

$55 + x +x =180\\\\2x=180-55\\\\2x=125\\\\\therefore x=\frac{125}{2} =62.5\°\\\\\therefore x=62.5\°$

The measure of Angle G is 62.5°.

8 0

3 years ago

Find the zeros of the function p(x) = -9x^2 + 1

morpeh [17]

Answer:

Zeros: 1/3 and -1/3

Step-by-step explanation:

You can solve this for the zeros by using the factoring method:

p(x) = (-3x-1)(3x-1)

Then, you take each factored equation and set it equal to zero:

-3x-1=0

3x-1=0

Then, solve for zero:

-3x=1 x=-1/3

3x=1 x=1/3

Your zeros are 1/3 and -1/3.

8 0

3 years ago