5. What is the probability of rolling a 4 on a number

Help please help help please please please

AnnZ [28]

Answer:

C. $\frac{5}{4}$

D. $\frac{6}{7}$

Step-by-step explanation:

C. $2 - \frac{12}{16}$

$= 2 - \frac{3}{4}$

$= \frac{8 - 3}{4}$

$= \frac{5}{4}$

D. $\frac{20}{22} \times \frac{33}{35}$

$= \frac{10}{11} \times \frac{33}{35}$

$= 10 \times \frac{3}{35}$

$= 2 \times \frac{3}{7}$

$= \frac{6}{7}$

3 0

3 years ago

The comprehensive strength of concrete is normally distributed with μ = 2500 psi and σ = 50 psi. Find the probability that a ran

VARVARA [1.3K]

Answer:

The probability that the diameter falls in the interval from 2499 psi to 2510 psi is 0.00798.

Step-by-step explanation:

Let's define the random variable, $X =$ "Comprehensive strength of concrete". We have information that $X$ is normally distributed with a mean of 2500 psi and a standard deviation of 50 psi (or a variance of 2500 psi). In other words, $X \sim N(2500, 2500)$ .

We want to know the probability of the mean of X or $\bar{X}$ that falls in the interval $[2499;2510]$ . From inference theory we know that :

$\bar{X} \sim N(2500, \frac{2500}{5}) \Rightarrow \bar{X} \sim N(2500,500)$

Now we can find the probability as follows:

$P(2499 \leq \bar{X} \leq 2510) \Rightarrow P(\frac{2499 - 2500}{500} \leq \frac{\bar{X} - 2500}{500} \leq \frac{2499 - 2500}{500} ) \Rightarrow\\\Rightarrow P(-0.002 \leq \frac{\bar{X} - 2500}{500} \leq 0.02 ) \Rightarrow P(-0.002 \leq Z \leq 0.02 )$

Where $Z \sim N(0,1)$ , then:

$P(-0.002 \leq Z \leq 0.02 ) \approx P(0 \leq Z \leq 0.02 ) = P(Z \leq 0.02 ) - P(Z \leq 0) \\P(0 \leq Z \leq 0.02 ) = 0.50798 - 0.5 = 0.00798$

8 0

4 years ago

Stacy earned $129.55 last week. Dave earned $127.95 last week. Carlos earned $127.05

noname [10]

Answer:

The total earnings is $384.55

The least earnings is

$127.05

$127.95

$129.55

5 0

3 years ago

Six times a number is 45 greater than the product of the number and -3. Find the number.

LiRa [457]

Answer:

5

Step-by-step explanation:

6a = (a*-3) + 45

then:

6a = -3a + 45

6a + 3a = 45

9a = 45

a = 45/9

a = 5

Check:

6*5 = (5*-3) + 45

30 = -15 + 45

8 0

3 years ago

I’ll give brainliest pls help

andrew11 [14]

Answer:

The slopes of WX and XZ

Step-by-step explanation:

The singular factor that determines if the parallelogram is a rectangle are the angles at the edges

Mathematically, we can only have a rectangle if there are four right angles with one right angle each at the edges of the rectangle

So, by having the slope of the sides forming the width and that which forms the length, we can deduce if what we have is rectangle given that the slopes will yield a perpendicular product

Hence, the slopes of WX and XZ can be calculated to show this

7 0

3 years ago