Which expression has a solution of 11, if m = 1? m - 11 11 + m 14

In a school , there are students and 30 teachers . Write the ratio of students to teachers

Tom [10]

How many students???

6 0

3 years ago

The lifetime of a certain type of battery is normally distributed with mean value 11 hours and standard deviation 1 hour. There

tankabanditka [31]

Answer:

The lifetime value needed is 11.8225 hours.

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by

$Z = \frac{X - \mu}{\sigma}$

After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we This p-value is the probability that the value of the measure is greater than X.

In this problem, we have that:

The lifetime of a certain type of battery is normally distributed with mean value 11 hours and standard deviation 1 hour. This means that $\mu = 11, \sigma = 1$ .

What lifetime value is such that the total lifetime of all batteries in a package exceeds that value for only 5% of all packages?

This is the value of THE MEAN SAMPLE X when Z has a pvalue of 0.95. That is between Z = 1.64 and Z = 1.65. So we use $Z = 1.645$

Since we need the mean sample, we need to find the standard deviation of the sample, that is:

$s = \frac{\sigma}{\sqrt{4}} = 0.5$

So:

$Z = \frac{X - \mu}{s}$

$1.645 = \frac{X - 11}{0.5}$

$X - 11 = 0.5*1.645$

$X = 11.8225$

The lifetime value needed is 11.8225 hours.

3 0

3 years ago

An ant can travel at a constant speed of 980 inches in every 5 minutes how far does the ant travel in 7 minutes

IrinaK [193]

Answer:

1372

Step-by-step explanation:

Because 980 divided by 5 is 196 and 196 x 5 = 980

So you take 196 and multiply it by 5 and it's 1372

Hope this helps :)

4 0

3 years ago

Kevin must take five tests in a math class. If his scores on the

Studentka2010 [4]

Answer:

95 %

Step-by-step explanation:

95 + 71 + 69 + 84 + 83 / 5 = 80.4

5 0

3 years ago

Read 2 more answers

In the triangle below, 4/5 represents which ratio?

ASHA 777 [7]

Answer:
sin (C)

Explanation:
In a right-angled triangle, special trig functions can be applied. These functions are as follows:
sin (theta) = $\frac{opposite}{hypotenuse}$

cos (theta) = $\frac{adjacent}{hypotenuse}$

tan (theta) = $\frac{opposite}{adjacent}$ 

Now, let's check the triangle we have:
We have two options:
First option:
5 is the hypotenuse of the triangle
4 is the side adjacent to angle B
Therefore, we can apply the cos function:
cos (B) = $\frac{4}{5}$ 

Second option:
5 is the hypotenuse of the triangle
4 is the side opposite to angle C
Therefore, we can apply the sin function:
sin (C) = $\frac{4}{5}$

Among the two options, the second one is the one found in the choices. Therefore, it will be the correct one.

Hope this helps :)

8 0

4 years ago

Read 2 more answers

Which expression has a solution of 11, if m = 1? m - 11 11 + m 14 - m m + 10