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3 years ago

Select the correct answer.

Mathematics

1 answer:

alexdok [17]3 years ago

8 0

Answer:

a. a straight line passing through the origin

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Find the measure of angle x in the figure below:

Solnce55 [7]

Answer:

30°

Step-by-step explanation:

180-75-75=30

6 0

3 years ago

A simple random sample of items resulted in a sample mean of . The population standard deviation is . a. Compute the confidence

Varvara68 [4.7K]

Answer:

(a): The 95% confidence interval is (46.4, 53.6)

(b): The 95% confidence interval is (47.9, 52.1)

(c): Larger sample gives a smaller margin of error.

Step-by-step explanation:

Given

$n = 30$ -- sample size

$\bar x = 50$ -- sample mean

$\sigma = 10$ --- sample standard deviation

Solving (a): The confidence interval of the population mean

Calculate the standard error

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {30}}$

$\sigma_x = \frac{10}{5.478}$

$\sigma_x = 1.825$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.825$

$E = 3.577$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 3.577$

$Lower = 46.423$

$Lower = 46.4$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 3.577$

$Upper = 53.577$

$Upper = 53.6$ --- approximated

So, the 95% confidence interval is (46.4, 53.6)

Solving (b): The confidence interval of the population mean if mean = 90

First, calculate the standard error of the mean

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {90}}$

$\sigma_x = \frac{10}{9.49}$

$\sigma_x = 1.054$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.054$

$E = 2.06584$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 2.06584$

$Lower = 47.93416$

$Lower = 47.9$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 2.06584$

$Upper = 52.06584$

$Upper = 52.1$ --- approximated

So, the 95% confidence interval is (47.9, 52.1)

Solving (c): Effect of larger sample size on margin of error

In (a), we have:

$n = 30$ $E = 3.577$

In (b), we have:

$n = 90$ $E = 2.06584$

Notice that the margin of error decreases when the sample size increases.

4 0

3 years ago

If Jemma recieved £69 everyday how much money would she get for a year

telo118 [61]

Answer:

£25185

Step-by-step explanation:

It depends on how many days are in your year. If it's a regular year, it's 365 days. If it's a leap year 366 days.

69 x 365 = 25185

69 x 366 = 25254

5 0

3 years ago

Read 2 more answers

PLS HELP! solve by completing the square x²+4x=8

masya89 [10]

Step-by-step explanation:

x²+4x=8

rearrange

x² + 4x - 8 = 0

half of 4 is 2

x² + 4x + 2² - 2² - 8 = 0

do x² + 4x + 2²

multiplies to give 4 adds to give 4

2+ 2

(x + 2)²

(x + 2)² - 2² - 8

(x + 2)² - 4 - 8

(x + 2)² - 12

(x + 2 + √12) (x + 2 - √12)

√12 = √4 * √3 = 2 √3

(x + 2 + 2√3) (x + 2 - 2√3)

4 0

3 years ago

4. Gina deposits $5,692 in a savings account paying 2.73% interest. To the

slava [35]

Answer:

B) 7867

Step-by-step explanation:

I = Prt

5 0

3 years ago