If 3(d+1)=4(d–2)<br> then what is the value of 5(d

Julie is a math tutor. She charges each student $210 for the first 7 hours of tutoring and $20 for each additional hour. When th

Nady [450]

A = 210 + 20(h - 7) <== ur equation

if she earns 410 tutoring...
410 = 210 + 20(h - 7)
410 = 210 + 20h - 140
410 = 20h + 70
410 - 70 = 20h
340 = 20h
340/20 = h
17 = h <=== she spent 17 hrs tutoring

8 0

3 years ago

Find three consecutive integers such that 4 times the least integer is 8 times two less the greatest integer.

patriot [66]

$least \: int = x \\ 4x = 8((x + 2) - 2) \\ 4x = 8x \\ 0 = 4x \\ 0 = x \\ numbers = 0 \: 1 \: 2$

6 0

3 years ago

A Department of Transportation report about air travel found that nationwide, 76% of all flights are on time. Base the following

ser-zykov [4K]

Answer:

30 flights are expected to be late.

Step-by-step explanation:

Consider the provided information.

A Department of Transportation report about air travel found that nationwide, 76% of all flights are on time.

That means 100-76% = 24% of all flights are not on time.

125 randomly selected flights.

We need to find flights would you expect to be late.

Flight expect to be late E(x) = nq

Here n is 125 and the probability of late is 24 or q = 0.24

Thus substitute the respective values in the above formula.

Flight expect to be late E(x) = 125 × 0.24 = 30

Hence, the 30 flights are expected to be late.

5 0

3 years ago

What is 1/2=q+2/3<br> help

alexandr1967 [171]

Answer:

Step-by-step explanation:

1/6

7 0

2 years ago

The standard deviation of math test scores at one high school is 16.1. A teacher claims that the standard deviation of the girls

Elanso [62]

Answer:

$\chi^2 =\frac{22-1}{259.21} 166.41 =13.482$

$p_v =P(\chi^2$

In order to find the p value we can use the following code in excel:

"=CHISQ.DIST(13.482,21,TRUE)"

If we compare the p value and the significance level provided we see that $p_v >\alpha$ so on this case we have enough evidence in order to FAIL reject the null hypothesis at the significance level provided. And that means that the population deviation is not significantly lower than 16.1 at 1% of significance.

Step-by-step explanation:

Notation and previous concepts

A chi-square test is "used to test if the variance of a population is equal to a specified value. This test can be either a two-sided test or a one-sided test. The two-sided version tests against the alternative that the true variance is either less than or greater than the specified value"

$n=22$ represent the sample size

$\alpha=0.01$ represent the confidence level

$s^2 =12.9^2=166.41$ represent the sample variance obtained

$\sigma^2_0 =16.1^2 =259.21$ represent the value that we want to test

Null and alternative hypothesis

On this case we want to check if the population deviation is smaller than 16.1 (that's equivalent to check if the population variance is lower than 259.21:

Null Hypothesis: $\sigma^2 \geq 259.21$

Alternative hypothesis: $\sigma^2$

Calculate the statistic

For this test we can use the following statistic:

$\chi^2 =\frac{n-1}{\sigma^2_0} s^2$

And this statistic is distributed chi square with n-1 degrees of freedom. We have eveything to replace.

$\chi^2 =\frac{22-1}{259.21} 166.41 =13.482$

Calculate the p value

In order to calculate the p value we need to have in count the degrees of freedom , on this case 21. And since is a left tailed test the p value would be given by:

$p_v =P(\chi^2$

In order to find the p value we can use the following code in excel:

"=CHISQ.DIST(13.482,21,TRUE)"

Conclusion

If we compare the p value and the significance level provided we see that $p_v >\alpha$ so on this case we have enough evidence in order to FAIL reject the null hypothesis at the significance level provided. And that means that the population deviation is not significantly lower than 16.1 at 1% of significance.

3 0

4 years ago

If 3(d+1)=4(d–2) then what is the value of 5(d–2)