Look at this graph:

Six years less than Tracey's age as an expression

likoan [24]

Answer:

T-6=X

Step-by-step explanation:

Tracey = T

X = Awnser

If we are subtracting six from Tracey's age, you would subtract six from T

since we don't know Tracey's age, it is represented by T.

Hope this Helps!

4 0

3 years ago

Fractions pt 2 cause lazy

Arada [10]

1/2 + 9/20 = 19/20
1/20 + 1/10 = 3/20
1/8 + 11/16 = 13/16
2/9 + 5/9 = 7/9
3/20 + 3/4 = 18/20 = 9/10
7/17 + 1/17 = 8/17

6 0

3 years ago

Read 2 more answers

What is an expression that equals 1 using the numbers 6, 3, and 5 only once

Gennadij [26K]

Answer: 1 = 6 - 5 + 3 × 0

8 0

3 years ago

At 95% confidence, how large a sample should be taken to obtain a margin of error of 0.03 for the estimation of a population pro

Gnom [1K]

Answer:

A sample of 1068 is needed.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

At 95% confidence, how large a sample should be taken to obtain a margin of error of 0.03 for the estimation of a population proportion?

We need a sample of n.

n is found when M = 0.03.

We have no prior estimate of $\pi$ , so we use the worst case scenario, which is $\pi = 0.5$

Then

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.03 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.03\sqrt{n} = 1.96*0.5$

$\sqrt{n} = \frac{1.96*0.5}{0.03}$

$(\sqrt{n})^{2} = (\frac{1.96*0.5}{0.03})^{2}$

$n = 1067.11$

Rounding up

A sample of 1068 is needed.

8 0

3 years ago

Lol what do I put so stuck

Sindrei [870]

Answer:

[See Below]

Step-by-step explanation:

Look at the "Fraction" column, all the fractions in this column must add up to 1 (because the whole bag contains only Red, Green, Blue or Other coloured beads).

So we work out the sum of missing fractions: $\frac{1}{12} + \frac{1}{4} = \frac{1}{12} + \frac{3}{12} = \frac{4}{12} = \frac{1}{3}$

And so we know the fractions in the missing boxes must add up to $1 - \frac{1}{3} = \frac{2}{3}$ .

This means that the number of blue and green beads is 2/3rds of the total number of beads in the bag. There are 12+4=16 blue+green beads so

$\frac{2}{3} \times \text{Number of beads} = 16 \Rightarrow \text{Number of beads} = 24$ .

So if there are 24 beads in the bag, then the red beads are 1/12th of 24 which is 2 and the other beads are 1/4 of 24 which is 6.

Finally to complete the missing fractions: there are 12 blue beads and 24 in total so the fraction of blue beads is 12/24 = 1/2. Similarly, there are 4 green beads so the fraction of green beads is 4/24 = 1/6.

(I thought this was a very tricky question. Let me know in the comments if something doesn't make sense, or if you need more explanation on any part, or even if you spot an easier way to do it that I can't.)

5 0

4 years ago