Unit test Evaluate the following expression. Sum 2+1x2 ng de racting

2. A jeweler bought an antique watch for $500. He then sold it in his store $850. What was the percent of change in the price of

Mars2501 [29]

Answer:

70% increase

Step-by-step explanation:

8 0

2 years ago

The girls in Lana’s troop set a goal to sell 1,000 boxes of cookies this year. There are 13 girls in the troop. At least how man

motikmotik

Answer:

$77$

Step-by-step explanation:

The troop wants to sell a minimum of 1,000 boxes, so we're looking for the smallest number of boxes they can sell and still meet the goal. Since there are 13 girls in the troop, take the ceiling (round up to the nearest whole number) of 1,000 divided by 13:

$\left\lceil \frac{1,000}{13}\right\rceil=\boxed{77}$

8 0

2 years ago

Read 2 more answers

The graph of a line passes through the points (0, 5) and (-10, 0). What is the equation of the line?

natta225 [31]

First find the slope:
y-y/x-x
5-0/0-(-10
5/+10
slope: 1/2
then use:
y-5. 1
--- = ---
x-0. 2
cross multiply.
2 (y-5)=1 (x-0)
2y-10=x
move the ten to the other side, switch the sign
2y=x+10
divide by 2
y=1/2x+5
final answer is
y=1/2x+5

5 0

3 years ago

Read 2 more answers

A study has indicated that the sample size necessary to estimate the average electricity use by residential customers of a large

Zanzabum

Answer:

$\sigma=547.1125$

Step-by-step explanation:

-The margin of error is calculated using the formula:

$ME=z_{\alpha/2}\times \frac{\sigma}{\sqrt{n}}\\\\$

-We substitute the values, n=900 and ME=30 in the formula to solve for standard deviation:

$ME=z_{\alpha/2}\times \frac{\sigma}{\sqrt{n}}\\\\\\30=1.645\times\frac{\sigma}{\sqrt{900}}\\\\\sigma=\frac{30^2}{1.645}\\\\=547.1125$

Hence, the population standard deviation is 547.1125

7 0

3 years ago

A sample of salary offers (in thousands of dollars) given to management majors is: 48, 51, 46, 52, 47, 48, 47, 50, 51, and 59. U

balu736 [363]

Answer:

Step-by-step explanation:

number of samples, n = 10

Mean = (48 + 51 + 46 + 52 + 47 + 48 + 47 + 50 + 51 + 59)/10 = 49.9

Standard deviation = √(summation(x - mean)/n

Summation(x - mean) = (48 - 49.9)^2 + (51 - 49.9)^2 + (46 - 49.9)^2+ (52 - 49.9)^2 + (47 - 49.9)^2 + (48 - 49.9)^2 + (47 - 49.9)^2 + (50 - 49.9)^2 + (51 - 49.9)^2 + (59- 49.9)^2 = 128.9

Standard deviation = √128.9/10 = 3.59

Confidence interval is written in the form,

(Sample mean - margin of error, sample mean + margin of error)

The sample mean, x is the point estimate for the population mean.

Margin of error = z × s/√n

Where

s = sample standard deviation

From the information given, the population standard deviation is unknown and the sample size is small, hence, we would use the t distribution to find the z score

In order to use the t distribution, we would determine the degree of freedom, df for the sample.

df = n - 1 = 10 - 1 = 9

Since confidence level = 95% = 0.95, α = 1 - CL = 1 – 0.95 = 0.05

α/2 = 0.05/2 = 0.025

the area to the right of z0.025 is 0.025 and the area to the left of z0.025 is 1 - 0.025 = 0.975

Looking at the t distribution table,

z = 2.262

Margin of error = 2.262 × 3.59/√10

= 2.57

the lower limit of this confidence interval is

49.9 - 2.57 = 47.33

the lower limit of this confidence interval is

49.9 + 2.57 = 52.47

So it is false

6 0

3 years ago