Y=-7x+4<br> Y=3/8x+-4<br> Y=16x+-1/5

An aircraft factory manufactures airplane engines. The unit cost (the cost in dollars to make each airplane engine) depends on t

Juliette [100K]

Answer:

Minimum unit cost = 5,858

Step-by-step explanation:

Given the function : C(x)=x^2−520x+73458

To find the minimum unit cost :

Take the derivative of C(x) with respect to x

dC/dx = 2x - 520

Set = 0

2x - 520

2x = 520

x = 260

To minimize unit cost, 260 engines must be produced

Hence, minimum unit cost will be :

C(x)=x^2−520x+73458

Put x = 260

C(260) = 260^2−520(260) + 73458

= 5,858

7 0

3 years ago

james has a board that is 3/4 long he wants to cut the board into 1/8 pieces how many pieces can james cut from the board write

Vilka [71]

The answer can be 6/1 or just 6. And visit www.caculatorsoup.com

4 0

3 years ago

A researcher claims that the mean of the salaries of elementary school teachers is greater than the mean of the salaries of seco

Brut [27]

Answer:

$t=\frac{(48250-45630)}{\sqrt{\frac{3900^2}{26}+\frac{5530^2}{24}}}}=1.921$

$df=n_{A}+n_{B}-2=26+24-2=48$

Since is a one sided test the p value would be:

$p_v =P(t_{(48)}>1.921)=0.0303$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can conclude that the mean for elementary school teachers is significantly higher than the mean for secondary teachers at 5% of significance

Step-by-step explanation:

Data given and notation

$\bar X_{A}=48250$ represent the mean of elementary teachers

$\bar X_{B}=45630$ represent the mean for secondary teachers

$s_{A}=3900$ represent the sample standard deviation for elementary teacher

$s_{B}=5530$ represent the sample standard deviation for secondary teachers

$n_{A}=26$ sample size selected

$n_{B}=24$ sample size selected

$\alpha=0.05$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean of the salaries of elementary school teachers is greater than the mean of the salaries of secondary school teachers, the system of hypothesis would be:

Null hypothesis: $\mu_{A}-\mu_{B}\leq 0$

Alternative hypothesis: $\mu_{A}-\mu_{B}>0$

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

$t=\frac{(\bar X_{A}-\bar X_{B})}{\sqrt{\frac{s^2_{A}}{n_{A}}+\frac{s^2_{B}}{n_{B}}}}$ (1)

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".

Calculate the statistic

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

$t=\frac{(48250-45630)}{\sqrt{\frac{3900^2}{26}+\frac{5530^2}{24}}}}=1.921$

P-value

The first step is calculate the degrees of freedom, on this case:

$df=n_{A}+n_{B}-2=26+24-2=48$

Since is a one sided test the p value would be:

$p_v =P(t_{(48)}>1.921)=0.0303$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can conclude that the mean for elementary school teachers is significantly higher than the mean for secondary teachers at 5% of significance

5 0

2 years ago

The mathematics department of a college has 7 male professors, 6 female professors, 12 male teaching assistants, and 7 female

Natalka [10]

Answer:

0.78125 or 78.125%

Step-by-step explanation:

Male professors = 7

Female professors = 6

Male T.A. = 12

Female T.A. = 7

Number of people in the department = 32

The probability that the selected person is a professor or a male is given by the probability that the person is a professor added to the probability that the person is a male, minus the probability that the person is a male professor:

$P( P\ or\ M) = P(P) +P(M) - P(P\ and\ M)\\P( P\ or\ M) =\frac{7+6}{32}+ \frac{7+12}{32}- \frac{7}{32} \\P( P\ or\ M) = 0.78125 = 78.125\%$

The probability is 0.78125 or 78.125%

6 0

3 years ago

Please that (b). I'm having some difficulties.

nata0808 [166]

Here's the answer.

Hope it helps u.

:)

7 0

3 years ago

Y=-7x+4 Y=3/8x+-4 Y=16x+-1/5