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3 years ago

PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!!

Mathematics

1 answer:

Nady [450]3 years ago

6 0

Answer: b) -0.625

<u>Step-by-step explanation:</u>

The formula for the z-score is:

$z=\dfrac{x-\mu}{\sigma}\\\\\bullet z \text{ is the z-score}\\\bullet x \text{ is the value}\\\bullet \mu \text{ is the mean}\\\bullet \sigma \text{ is the standard deviation}\\\\z=\dfrac{6-8}{3.2}\\\\\\.\ =\dfrac{-2}{3.2}\\\\\\.\ =\large\boxed{-.0625}$

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Hi pls help me!!! thank you

elena-s [515]

Step-by-step explanation:

Circumference (C):

$C = 2\pi r = 2\pi(5\:\text{ft}) = 31.4\:\text{ft}$

Area (A):

$A = \pi r^2 = \pi(5\:\text{ft})^2 = 78.5\:\text{ft}^2$

6 0

2 years ago

BRAINLIEST WILL BE MARKED

zubka84 [21]

Answer:

B. input

Step-by-step explanation:

8 0

3 years ago

From experience, it is known that on average 10% of welds performed by a particular welder are defective. if this welder is requ

bulgar [2K]

Binomial distribution can be used because the situation satisfies all the following conditions:1. Number of trials is known and remains constant (n)2. Each trial is Bernoulli (i.e. exactly two possible outcomes) (success/failure)3. Probability is known and remains constant throughout the trials (p)4. All trials are random and independent of the othersThe number of successes, x, is then given by $P(x)=C(n,x)p^x(1-p)^{n-x}$ where $C(n,x)=\frac{n!}{x!(n-x)!}$
Here we're given
p=0.10 [ success = defective ]
n=3

(a) x=0
$P(x)=C(n,x)p^x(1-p)^{n-x}$
$=C(3,0)0.1^0(1-0.1)^{3-0}$
$=1(1)(0.729)$
$=0.729$

(b) x=2
$P(x)=C(n,x)p^x(1-p)^{n-x}$
$=C(3,2)0.1^2(1-0.1)^{3-2}$
$=3(0.01)(0.9)$
$=0.027$

(c) x ≥ 2
$P(x)=\sum_{x=2}^3C(n,x)p^x(1-p)^{n-x}$
$=P(2)+P(3)$
$=C(n,2)p^2(1-p)^{n-2}+C(n,3)p^3(1-p)^{n-3}$
$=C(3,2)0.1^2(1-0.1)^{3-2}+C(3,3)0.1^3(1-0.1)^{3-3}$
$=3(0.01)(0.9)+1(0.001)1$
$=0.027+0.001$
$=0.028$

8 0

3 years ago

9.4 The heights of a random sample of 50 college stu- dents showed a mean of 174.5 centimeters and a stan- dard deviation of 6.9

gladu [14]

Answer: a) (176.76,172.24), b) 0.976.

Step-by-step explanation:

Since we have given that

Mean height = 174.5 cm

Standard deviation = 6.9 cm

n = 50

we need to find the 98% confidence interval.

So, z = 2.326

(a) Construct a 98% confidence interval for the mean height of all college students.

$x\pm z\times \dfrac{\sigma}{\sqrt{n}}\\\\=(174.5\pm 2.326\times \dfrac{6.9}{\sqrt{50}})\\\\=(174.5+2.26,174.5-2.26)\\\\=(176.76,172.24)$

(b) What can we assert with 98% confidence about the possible size of our error if we estimate the mean height of all college students to be 174.5 centime- ters?

Error would be

$\dfrac{\sigma}{\sqrt{n}}\\\\=\dfrac{6.9}{\sqrt{50}}\\\\=0.976$

Hence, a) (176.76,172.24), b) 0.976.

8 0

3 years ago

Becky spends 3/5 of her money she has left £60 left. how much money did she start with?

Virty [35]

Answer: $150

Step-by-step explanation:

Becky spends 3/5 of her Money and is left with 2/5 of her money.

Hence 2 parts = $60

And 5 parts = $150

Becky has $150 at first.

5 0

3 years ago