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5 months ago

Find the sum.. 7/4 − (−1/2) Please Help! I need it now!

Mathematics

2 answers:

8090 [49]5 months ago

8 0

Answer:

1.25

Step-by-step explanation:

SSSSS [86.1K]5 months ago

8 0

Answer:1.25

Step-by-step explanation:

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I just need help on this.<br>

Arturiano [62]

Answer:

.42 is an answer that will work.

4 0

2 years ago

Read 2 more answers

The lengths of nails produced in a factory are normally distributed with a mean of 4.84 centimeters and a standard deviation of

Helga [31]

Answer:

Top 3%: 4.934 cm

Bottom 3%: 4.746 cm

Step-by-step explanation:

Problems of normally distributed samples are 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:

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

The Z-score measures how many standard deviations the measure is from the mean. 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 get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 4.84, \sigma = 0.05$

Top 3%

Value of Z when Z has a pvalue of 1 - 0.03 = 0.97. So X when Z = 1.88.

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

$1.88 = \frac{X - 4.84}{0.05}$

$X - 4.84 = 0.05*1.88$

$X = 4.934$

Bottom 3%

Value of Z when Z has a pvalue of 0.03. So X when Z = -1.88.

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

$-1.88 = \frac{X - 4.84}{0.05}$

$X - 4.84 = 0.05*(-1.88)$

$X = 4.746$

8 0

2 years ago

{[20/(8+2)]^6+6}/(4^2/2)

Naddika [18.5K]

So for this problem we need to do order of operations so the very first step that we need to do here is (8+2) because that is the smallest enclosed symbols (8+2)=10 next divide by 20 because that is the next step in the equation which 20/10=2, so now we have {[2]^6+6} and due to order of operations the next step here is to take 2 to the power of 6 which is 64 so now we have {64+6} which is 70 so now we have 70/(4^2/2) and due to order of operations we do the parentheses first and that would mean that we do 4^2 because exponents come after parantheses like so,
70/(16/2) now we do 16/2 because its still inside the paranthesess so 16/2=8 so now we have 70/8 and that equals are end answer of 8.75 Enjoy!=)

7 0

2 years ago

Read 2 more answers

The sum of three consecutive integers is 9.

devlian [24]

Answer:

3rd integer:n+2

Step-by-step explanation:

6 0

2 years ago

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A rare form of malignant tumor occurs in 11 children in a million, so its probability is 0.000011. Four cases of this tumor occ

Shkiper50 [21]

Answer:

a) The mean number of cases is 0.14608 cases.

b) The probability that the number of cases is exactly 0 or 1 is 0.990.

c) The probability of more than one case is 0.010

d) No, because the probability of more than one case is very small

Step-by-step explanation:

We can model this problem with a Poisson distribution, with parameter:

$\lambda=r*t=0.000011*13,280=0.14608$

a) The mean amount of cases is equal to the parameter λ=0.14608.

b) The probability of having 0 or 1 cases is:

$P(k=0)=\frac{\lambda^0 e^{-\lambda}}{0!}=\frac{1*0.864}{1} =0.864\\\\ P(k=1)=\frac{\lambda^1 e^{-\lambda}}{0!}=\frac{0.14608*0.864}{1} =0.126\\\\P(k\leq1)=0.864+0.126=0.990$

c) The probability of more than one case is:

$P(k>1)=1-P(k\leq 1)=1-0.990=0.010$

d) The cluster of 4 cases can not be due to pure chance, as it is a very high proportion of cases according to the average rate. Just having more than one case has a probability of 1%.

7 0

2 years ago