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3 years ago

Plz help! anybody. i'll mark brainliest 20 points!!!!

Mathematics

1 answer:

lisabon 2012 [21]3 years ago

5 0

(1) Snow fall in last week = $3 \frac{1}{2}$ inches

Snow fall in today= $5 \frac{3}{4}$ inches

Let us first change mixed fraction to improper fraction.

$\begin{aligned}&3 \frac{1}{2}=\frac{7}{2}\\&5 \frac{3}{4}=\frac{23}{4}\end{aligned}$

Now, make the denominators same.

$3 \frac{1}{2}=\frac{7}{2}=\frac{7 \times 2}{2 \times 2}=\frac{14}{4}$ , $5 \frac{3}{4}=\frac{23}{4}$

Now, find the difference between 14/4 and 23/4.

$\frac{23}{4}-\frac{14}{4}=\frac{9}{4}=2 \frac{1}{4}$

So, compared to last week $2 \frac{1}{4}$ more inches of snow fell today.

(2) Given three times a number, minus nine, equals six times six, divided by four.

Let a number be X.

3X – 9 = 6 × 6/4

(3) To solve the equation:

3X – 9 = 6 × 6/4

3X – 9 = 36/4

3X – 9 = 9

3X = 18

X = 6

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A club consisting of 6 juniors and 8 seniors is to be formed from a group of 13 juniors and 16 seniors. How many different clubs

Vilka [71]

Answer: 22,084,920 different clubs

Step-by-step explanation:

The club must have 6 juniors and 8 seniors

We have a total of 13 juniors and 16 seniors.

Now, we know that the possible combinations of N objects into a group of K is equal to:

$C = \frac{N!}{(N-K)!*K!}$

For the juniors we have N = 13 and K = 6

$Cj = \frac{13!}{7!*6!} = \frac{13*12*11*10*9*8}{6*5*4*3*2*1} = 1716$

For the seniors we have N = 16 and K = 8

$Cs = \frac{16!}{8!8!} = \frac{16*15*14*13*12*11*10*9}{8*7*6*5*4*3*2*1} = 12870$

Now, as the group consist on both combinations togheter, the number of different clubs that can be formed are:

C = Cj*Cs = 1,716*12,870 = 22,084,920

5 0

3 years ago

Laser scanning for fish volume estimation. engineers design tanks for rearing commercial fish to minimize both the use of natura

AVprozaik [17]

Answer:

The 99% confidence interval would be given by (196.2;283.8)

We are 99% condident that the true mean is between 196.2 and 283.8

We need to assume that the data comes from a random sample and we need to assume that the distribution of the data is normal.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X=240$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=15 represent the sample standard deviation

n=4 represent the sample size

Part a

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=4-1=3$

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,3)".And we see that $t_{\alpha/2}=5.84$

Now we have everything in order to replace into formula (1):

$240-5.84\frac{15}{\sqrt{4}}=196.2$

$240+5.84\frac{15}{\sqrt{4}}=283.8$

So on this case the 99% confidence interval would be given by (196.2;283.8)

We are 99% condident that the true mean is between 196.2 and 283.8

What assumption about the data is necessary for the inference derived from the analysis to be valid?

We need to assume that the data comes from a random sample and we need to assume that the distribution of the data is normal.

4 0

3 years ago

Simplify this expression <br> Thank you :)

Anna11 [10]

Im not entirely sure but i got 3x^2y

6 0

3 years ago

Nina can ride her bike 63,360 feet in 3,400 seconds, and Sophia can ride her bike 10 miles in 1 hour. What is Nina's rate in mil

avanturin [10]

5,280 feet → 1 mile
63,360 feet → 63,360/5,280 = 12 miles

60 x 60 seconds → 1 hour
3,400 seconds → 3,400/3,600 = 17/18 hours

Nina's rate = 12 miles / (17/18) hours = 12 12/17 miles per hour.

4 0

3 years ago

There are two sets of rainfall data for two different time periods in the same location.

Monica [59]

Answer:

two different time periods in the same location.

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What type of visual display could be used to compare the two data sets?

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3 years ago

Read 2 more answers