Which of the following expressions is equivalent to -9?

In a certain test, the number of successful candidates was three times than that of unsuccessful candidate, if there had been 16

Natali5045456 [20]

Answer:

The number of candidates is 136.

Step-by-step explanation:

3 0

3 years ago

A simple random sample of size nequals10 is obtained from a population with muequals68 and sigmaequals15. (a) What must be true

valentina_108 [34]

Answer:

(a) The distribution of the sample mean ( $\bar x$ ) is N (68, 4.74²).

(b) The value of $P(\bar X$ is 0.7642.

(c) The value of $P(\bar X\geq 69.1)$ is 0.3670.

Step-by-step explanation:

A random sample of size n = 10 is selected from a population.

Let the population be made up of the random variable X.

The mean and standard deviation of X are:

$\mu=68\\\sigma=15$

(a)

According to the Central Limit Theorem if we have a population with mean μ and standard deviation σ and we take appropriately huge random samples (n ≥ 30) from the population with replacement, then the distribution of the sample mean will be approximately normally distributed.

Since the sample selected is not large, i.e. n = 10 < 30, for the distribution of the sample mean will be approximately normally distributed, the population from which the sample is selected must be normally distributed.

Then, the mean of the distribution of the sample mean is given by,

$\mu_{\bar x}=\mu=68$

And the standard deviation of the distribution of the sample mean is given by,

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{15}{\sqrt{10}}=4.74$

Thus, the distribution of the sample mean ( $\bar x$ ) is N (68, 4.74²).

(b)

Compute the value of $P(\bar X$ as follows:

$P(\bar X$

$=P(Z$

*Use a z-table for the probability.

Thus, the value of $P(\bar X$ is 0.7642.

(c)

Compute the value of $P(\bar X\geq 69.1)$ as follows:

Apply continuity correction as follows:

$P(\bar X\geq 69.1)=P(\bar X> 69.1+0.5)$

$=P(\bar X>69.6)$

$=P(\frac{\bar X-\mu_{\bar x}}{\sigma_{\bar x}}>\frac{69.6-68}{4.74})$

$=P(Z>0.34)\\=1-P(Z$

Thus, the value of $P(\bar X\geq 69.1)$ is 0.3670.

7 0

3 years ago

Which decimal has the greater value: 8,516.50 or 8,516.90?

Lerok [7]

8,516.90 has the greater value.

4 0

3 years ago

Read 2 more answers

HELP PLZ PICTURE^ Need it asap porfa

timurjin [86]

Answer:

it has one solution

Step-by-step explanation:

1.y=x-3

2. 3y-3x sub x-3 in place of y therefore

it can also be written as 3x-3x-9=9

if you add 9 to both sides 3x-3x-9+9=-9+9

0+0=0

3 0

3 years ago

The sketch shows the distance three runners travel during a race. Describe what occurs at times A,B,C and D. In what order do th

goldfiish [28.3K]

Answer:

Notice that the distance is in the y-axis, and the time in the x-axis.

First, let's see what happens in the four points:

A) You can see that in point A, the steepness of the line increases, this means that the speed of the runner increases in that point.

B) In this point, the runner that increased his/her speed in point A crosses the graph of another runner, this means that they are at the same distance to the end and at the same time.

C) In this point again two runners are at the same distance and the same time, and we also can see that the runer that increased his/her speed at point A, now has reached the end of the race (because his line stops increasing, wich means that he/she already finished the race)

D) The las runner finishes the race at point D.

Then the first runner that finishes the race is the one with the shorter graph (shorter graph means that he ran for less time than the others, wich means that he/she finished first)

The last runner is the one that finished at point D,

The middle one finishes right after the point C.

6 0

3 years ago