Please help, 16 points and i’ll mark you as brainlest

45 of the 80 children in the club or girls what was the ratio of boys to girls in the club?

Oxana [17]

There are 80 children. 45 of them are girls. The amount of boys is equal to:

$80-45 = 35$

That means there are 45 girls and 35 boys.

The ratio of boys to girls is: $35:45$

Simplify:

$35 \div 5 = 7 \\ 45 \div 5 = 9 \\ \\35:45 \rightarrow 7:9$

Your answer is 7:9

5 0

3 years ago

The sugar content of the syrup in canned peaches is normally distributed. A random sample of n = 10 cans yields a sample standar

Serggg [28]

Answer:

The 95% confidence interval is given by:

3.30<σ<8.76

Step-by-step explanation:

1) Data given and notation

s=4.798 represent the sample standard deviation

$\bar x$ represent the sample mean

n=10 the sample size

Confidence=95% or 0.95

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 mean or variance 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.

The Chi Square distribution is the distribution of the sum of squared standard normal deviates .

2) Calculating the confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

$df=n-1=10-1=9$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a tabel to find the critical values.

The excel commands would be: "=CHISQ.INV(0.025,9)" "=CHISQ.INV(0.975,9)". so for this case the critical values are:

$\chi^2_{\alpha/2}=19.022$

$\chi^2_{1- \alpha/2}=2.700$

And replacing into the formula for the interval we got:

$\frac{(9)(4.798)^2}{19.022} \leq \sigma \frac{(9)(4.798)^2}{2.700}$

$10.892 \leq \sigma^2 \leq 76.736$

Now we just take square root on both sides of the interval and we got:

$3.30 \leq \sigma \leq 8.76$

So the best option would be:

3.30<σ<8.76

7 0

3 years ago

What is the solution to the system of equations?

alukav5142 [94]

Answer:

(x, y) = (-4, 15)

Step-by-step explanation:

The two equations have the same coefficient for y, so you can eliminate y by subtracting one equation from the other. Here the x coefficient is largest for the first equation, so it will work best to subtract the second equation.

(3x +y) -(2x +y) = (3) -(7)

x = -4 . . . . . . . . simplify

Now, we can find y by substituting this value for x.

2(-4) +y = 7

y = 7 +8 = 15 . . . . . add 8 to both sides of the equation

The solution is (x, y) = (-4, 15).

6 0

3 years ago

T F IfA and B are similar matrices, then AT=BT

muminat

Answer:

Step-by-step explanation: