A plane travels at a constant speed. It takes 7 hours to travel 3,780 miles. What is the plane’s speed in miles per hour.

A company employs two shifts of workers. Each shift produces a type of gasket where the thickness is the critical dimension. The

Oksanka [162]

Answer:

a) $[-0.134,0.034]$

b) We are uncertain

c) It will change significantly

Step-by-step explanation:

a) Since the variances are unknown, we use the t-test with 95% confidence interval, that is the significance level = 1-0.05 = 0.025.

Since we assume that the variances are equal, we use the pooled variance given as

$s_p^2 = \frac{ (n_1 -1)s_1^2 + (n_2-1)s_2^2}{n_1+n_2-2}$ ,

where $n_1 = 40, n_2 = 30, s_1 = 0.16, s_2 = 0.19$ .

The mean difference $\mu_1 - \mu_2 = 10.85 - 10.90 = -0.05$ .

The confidence interval is

$(\mu_1 - \mu_2) \pm t_{n_1+n_2-2,\alpha/2} \sqrt{\frac{s_p^2}{n_1} + \frac{s_p^2}{n_2}} = (-0.05) \pm t_{68,0.025} \sqrt{\frac{0.03}{40} + \frac{0.03}{30}}$

$= -0.05\pm 1.995 \times 0.042 = -0.05 \pm 0.084 = [-0.134,0.034]$

b) With 95% confidence, we can say that it is possible that the gaskets from shift 2 are, on average, wider than the gaskets from shift 1, because the mean difference extends to the negative interval or that the gaskets from shift 1 are wider, because the confidence interval extends to the positive interval.

c) Increasing the sample sizes results in a smaller margin of error, which gives us a narrower confidence interval, thus giving us a good idea of what the true mean difference is.

6 0

4 years ago

Please Help..........................

jasenka [17]

The exact circumference is 60ft

8 0

4 years ago

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What does "Classify the polynomial by the number of terms" mean

soldier1979 [14.2K]

"Classify the polynomial by the number of terms" means a term contains both the variables and its coefficient. For example a "monomial" has one term like $2x^{2}$ .

A binomial has 2 terms like $3x^{2}+6x$

A trinomial has 3 terms like $4x^{2}+5x-8$

And a polynomial has 4 or more terms.

So basically one can classify the type of polynomial by counting the number of terms in a given equation.

5 0

3 years ago

Combined, Teresa and Janey have saved $345 dollars. Teresa has saved twice as much as Janey. How much money do they each have?

Tema [17]

Answer: Janey has $115, and Teresa has $230.

Step-by-step explanation:

Set x be the money that Janey have, then Teresa have 2x.

x + 2x = 345

3x = 345

x= $115

2x= 2(115)= $230

6 0

3 years ago

Choose the correct answers for (a) the total installment price, (b) the carrying charges, and (c) the number of months needed to

Brrunno [24]

Part A:

Given that <span>a dinette table with a cash price of $200 is purchased at $8.50 down and $11.00 per month for 24 months

The total installment price is given by

$P=\$8.50+\$11(24) \\ \\ =\$8.50+\$264=\$272.50$

Part B:

The carrying charges is given by the total installation price minus the cash price.

From part a, we obtained that the total installation price is $272.50 and given that the cash price is $200.

Therefore, the carrying charges is given by

$272.50 - $200.00 = $72.00

Part C:

If the money is to be saved at $11 per month to be able to purchase the table at the cash price, the number of months it will take to be able to save $200 at $11 per month is given by

$\frac{\$200}{\$11} =18.18\, months$

Therefore, it will take 19 months </span><span>to save the money at the monthly rate needed to buy the item for its cash price.</span>

3 0

3 years ago

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