I need help with m-3 over 4 = m-3 over 5

Graph 24x+25=−6y+7 . (if you can please give me the coordinates)

dexar [7]

(-0.75,0)-(0,3) is the answer

7 0

3 years ago

The following data lists the ages of a random selection of actresses when they won an award in the category of Best Actress, al

Valentin [98]

Answer:

a) $p_v =P(t_{(9)}$

The p value is higher than the significance level given 0.01, so then we can conclude that we FAIL to reject the null hypothesis. And we can say that the true difference for Best Actresses is not significantly lower than the mean for Best Actors at 1% of significance.

b) The 99% confidence interval would be given by (-21.469;2.069)

c) We got the same conclusion as part a, sicne the confidence interval contains the value 0, we FAIL to reject the null hypothesis that the difference between the two

Step-by-step explanation:

Part a

Let put some notation

x=actor's age , y = actress's age

x: 58 41 36 36 34 33 48 37 37 43

y: 26 27 34 26 35 29 23 42 30 34

The system of hypothesis for this case are:

Null hypothesis: $\mu_y- \mu_x \geq 0$

Alternative hypothesis: $\mu_y -\mu_x$

The first step is calculate the difference $d_i=y_i-x_i$ and we obtain this:

d: -32, -14, -2, -10, 1, -4, -25, 5, -7, -9

The second step is calculate the mean difference

$\bar d= \frac{\sum_{i=1}^n d_i}{n}= -9.7$

The third step would be calculate the standard deviation for the differences, and we got:

$s_d =\frac{\sum_{i=1}^n (d_i -\bar d)^2}{n-1} =11.451$

The 4 step is calculate the statistic given by :

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=\frac{-9.7 -0}{\frac{11.451}{\sqrt{10}}}=-2.679$

The next step is calculate the degrees of freedom given by:

$df=n-1=10-1=9$

Now we can calculate the p value, since we have a left tailed test the p value is given by:

$p_v =P(t_{(9)}$

The p value is higher than the significance level given 0.01, so then we can conclude that we FAIL to reject the null hypothesis. And we can say that the true difference for Best Actresses is not significantly lower than the mean for Best Actors at 1% of significance.

Part b

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The confidence interval for the mean is given by the following formula:

$\bar d \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,9)".And we see that $t_{\alpha/2}=3.25$

Now we have everything in order to replace into formula (1):

$-9.7-3.25\frac{11.451}{\sqrt{10}}=-21.469$

$-9.7+3.25\frac{11.451}{\sqrt{10}}=2.069$

So on this case the 99% confidence interval would be given by (-21.469;2.069)

Part c

We got the same conclusion as part a, sicne the confidence interval contains the value 0, we FAIL to reject the null hypothesis that the difference between the two means is 0.

8 0

3 years ago

An instructor who taught two sections of engineering probability last term, the first with 20 students and thesecond with 30, de

Oliga [24]

Answer:

0.207

Step-by-step explanation:

This is an hypergeometric distribution problem

An hypergeometric distribution has the same sense as the discrete probabilities of binomial distribution, but unlike binomial distribution, hypergeometric distribution does not allow replacement.

Binomial distribution expresses the probability of picking k objects from n with replacement, but hypergeometric distribution expresses picking k objects from n without replacement, with the finite total population, N, containing K objects.

It is expressed mathematically as

h(k: n, K, N) = (ᴷCₖ)(ᴺ⁻ᴷCₙ₋ₖ)/(ᴺCₙ)

where

k = number of students in the 2nd section required to be in the first 15 graded projects (number of successes) = 10

n = total number of first graded projects (number of trials) = 15

K = number of students in the 2nd section of the class = 30

N = total number of students = 50

h(10: 15, 30, 50) = (³⁰C₁₀)(⁵⁰⁻³⁰C₁₅₋₁₀)/(⁵⁰C₁₅)

h(10: 15, 30, 50) = (³⁰C₁₀)(²⁰C₅)/(⁵⁰C₁₅)

= (30,045,015)(15,504)/(2,250,829,575,120)

P(X = 10) = 0.207

Hope this Helps!!!

7 0

3 years ago

Solve for x !!!!!!!!

xeze [42]

Answer:

D) 4

Step-by-step explanation:

By remote interior angle property if a triangle, we have:

19x° + (18x - 4)° = 144°

(18x - 4 + 19x)° = 144°

(37x - 4)° = 144°

37x - 4 = 144

37x = 144 + 4

37x = 148

x = 148/37

x = 4

4 0

3 years ago

Read 2 more answers

A man drove his car at 80km per hr for 1 and a quarter hrs .He rested for 45mins and then covered 240km, at the same time. Calcu

prisoha [69]

Answer:

Probably 128 km/h, but maybe 98.5 km/h. See below.

Step-by-step explanation:

What does "at the same time" mean?

If it means that he covered the 240 km in the same time as he convered the 80 km, then this is how you solve it:

80 km in 1.25 hour

240 km in 1.25 hour

Total distance: 80 km + 240 km = 320 km

Total time: 1.25 hour + 1.25 hour = 2.5 hour

average speed = (total distance)/(total time) = 320 km / 2.5 hour = 128 km/h

If it means he covered the 240 km in the same time he covered the 80 km plus the rest, then this is how you solve it:

80 km in 1.25 hour

240 km in 1.25 hour + 45 min = 240 km in 1.25 houir + 0.75 hour = 240 km in 2 hour

Total distance: 80 km + 240 km = 320 km

Total time: 1.25 hour + 2 hour = 3.25 hour

average speed = (total distance)/(total time) = 320 km / 3.25 hour = 98.5 km/h

3 0

3 years ago