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bogdanovich [222]

3 years ago

13

A club puts its members into 5 groups for an activity. After 7 students have to leave early, there are only 3 students left to f

inish the activity. How many students were in each group?

1 answer:

soldier1979 [14.2K]3 years ago

6 0

Answer:

I think that there were 12 students in each group fam.

Step-by-step explanation:

I dont really know so dont get mad at me if i am wrong dude

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Which type of business would tend to use bank loans?

trasher [3.6K]

All business due this; probably locally own.

4 0

2 years ago

Two machines are used for filling glass bottles with a soft-drink beverage. The filling process have known standard deviations s

stellarik [79]

Answer:

a. We reject the null hypothesis at the significance level of 0.05

b. The p-value is zero for practical applications

c. (-0.0225, -0.0375)

Step-by-step explanation:

Let the bottles from machine 1 be the first population and the bottles from machine 2 be the second population.

Then we have $n_{1} = 25$ , $\bar{x}_{1} = 2.04$ , $\sigma_{1} = 0.010$ and $n_{2} = 20$ , $\bar{x}_{2} = 2.07$ , $\sigma_{2} = 0.015$ . The pooled estimate is given by

$\sigma_{p}^{2} = \frac{(n_{1}-1)\sigma_{1}^{2}+(n_{2}-1)\sigma_{2}^{2}}{n_{1}+n_{2}-2} = \frac{(25-1)(0.010)^{2}+(20-1)(0.015)^{2}}{25+20-2} = 0.0001552$

a. We want to test $H_{0}: \mu_{1}-\mu_{2} = 0$ vs $H_{1}: \mu_{1}-\mu_{2} \neq 0$ (two-tailed alternative).

The test statistic is $T = \frac{\bar{x}_{1} - \bar{x}_{2}-0}{S_{p}\sqrt{1/n_{1}+1/n_{2}}}$ and the observed value is $t_{0} = \frac{2.04 - 2.07}{(0.01246)(0.3)} = -8.0257$ . T has a Student's t distribution with 20 + 25 - 2 = 43 df.

The rejection region is given by RR = {t | t < -2.0167 or t > 2.0167} where -2.0167 and 2.0167 are the 2.5th and 97.5th quantiles of the Student's t distribution with 43 df respectively. Because the observed value $t_{0}$ falls inside RR, we reject the null hypothesis at the significance level of 0.05

b. The p-value for this test is given by $2P(T$ 0 (4.359564e-10) because we have a two-tailed alternative. Here T has a t distribution with 43 df.

c. The 95% confidence interval for the true mean difference is given by (if the samples are independent)

$(\bar{x}_{1}-\bar{x}_{2})\pm t_{0.05/2}s_{p}\sqrt{\frac{1}{25}+\frac{1}{20}}$ , i.e.,

$-0.03\pm t_{0.025}0.012459\sqrt{\frac{1}{25}+\frac{1}{20}}$

where $t_{0.025}$ is the 2.5th quantile of the t distribution with (25+20-2) = 43 degrees of freedom. So

$-0.03\pm(2.0167)(0.012459)(0.3)$ , i.e.,

(-0.0225, -0.0375)

8 0

2 years ago

The difference between twice a number and three is equal to six decreased by the number find the number

devlian [24]

Translate the English to Math language:

Let x be that number

2x -3 = x-6 solve for x ; x=-3

5 0

2 years ago

Factor the following polynomial written in standard form. B^2-14B+49

Vladimir79 [104]

After factoring $B^2-14B+49$ we get $(B-7)(B-7)$

Step-by-step explanation:

We need to factorize the polynomial:

$B^2-14B+49$

Factorization is done by breaking the middle term such that the sum is equal to the middle value of polynomial and product is equal to product of first and last term in the polynomial.

So, Factorizing:

$B^2-14B+49\\=B^2-7B-7B+49\\=B(B-7)-7(B-7)\\=(B-7)(B-7)$

So, After factoring $B^2-14B+49$ we get $(B-7)(B-7)$

Keywords: Factorization, Factors

Learn more about factors at:

#learnwithBrainly

8 0

3 years ago

Some of answers use 3,14 as a substitute for pi.

Katena32 [7]

Personally i think that if you use the pi symbol it would be more accurate because on a calculator there is an pi symbol √ which is the same it will give you an answer closer to an whole number.

4 0

2 years ago