Solve the equation and enter the value of x below.<br> x + 29 = 49<br> X =

A sample size must be determined for estimating a population mean given that the confidence level is % and the desired margin o

Sauron [17]

Complete Question

The complete question is shown on the first uploaded image

Answer:

a

$n =290$

b

$n =129$

c

The correct option is D

Step-by-step explanation:

From the question we are told that

The margin of error is $E = 0.23$

The largest value is k = 15

The smallest value is u = 7

From the question we are told the confidence level is 95% , hence the level of significance is

$\alpha = (100 - 95 ) \%$

=> $\alpha = 0.05$

Generally from the normal distribution table the critical value of $\frac{\alpha }{2}$ is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally population standard deviation estimate is mathematically represented as

$\sigma = \frac{Range }{4}$

Here the Range is mathematically represented as

$Range = k - u$

=> $Range = 15 - 7$

=> $Range = 8$

=> $\sigma = \frac{8 }{4}$

=> $\sigma = 2$

Generally the sample size is mathematically represented as

$n = [\frac{Z_{\frac{\alpha }{2} } * \sigma }{E} ] ^2$

=> $n = [1.96 * 2 }{0.23} ] ^2$

=> $n =290$

Generally to obtain a conservatively small sample size the population standard deviation estimate becomes

=> $\sigma = \frac{Range }{6}$

=> $\sigma = \frac{8 }{6}$

=> $\sigma =1.333$

Generally the conservatively small sample size is mathematically evaluated as

$n = [\frac{Z_{\frac{\alpha }{2} } * \sigma }{E} ] ^2$

=> $n = [1.96 * 1.333 }{0.23} ] ^2$

=> $n =129$

6 0

2 years ago

For a special order, The ABC company manufactured 400 shirts. Sweatshirts were priced at $35 each and T-shirts at $25 each. The

hodyreva [135]

Answer:

Thy bought 150 Sweatshirts (x) and 250 tshirts (y)

Step-by-step explanation:

35x + 25y = 11500

x + y = 400

-25 (x + y = 400) Multiply by -25 to get the y's to disappear when you add the two equations together

-25x - 25y = 10000

10x =1500

x = 150

Plug 150 in either equation for x to find y

150 + y = 400

y = 250

6 0

2 years ago

8x + 2+ 4y; x = 9, y = 2

Alchen [17]

Answer: 82

Step-by-step explanation:

We simply need to substitute the values for x and y into the equation

Both variables are already given to us, x=9, y=2

8(9)+2+4(2)

72+2+8

82

4 0

2 years ago

How do you solve 3 1/4 - 1 5/6

rjkz [21]

Answer:

to solve $3\frac{1}{4} -1\frac{5}{6}$ you would first need to convert them from mixed numbers to improper fractions. You can do this by multiplying the denominator with the whole number and then adding the numerator. Then you should make sure that the denominators are the same. You can do this by first finding a number that they will both multiply into. In this example it is 12. And when changing the denominator you must apply it to the numerator. So if you multiplied the denominator by 3 then you must multiply the numerator by 3. After you can just minus the numerators. However remember to keep the denominator the same. Then you can change it back into a mixed number by dividing the numerator by the denominator and having that whole number on the side of the fraction . lets say it is $\frac{13}{6}$ then you would divide 13 by 6 which is 2 and a decimal and then minus the number that is multiplied by the numerator and it will give a number that is smaller than the denominator and then it would become $2\frac{1}{6}$ .