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stealth61 [152]
3 years ago
13

The sum of two numbers is 20.8 and their difference os 10.2. Find these numbers.

Mathematics
1 answer:
Slav-nsk [51]3 years ago
6 0

Answer:

the numbers are 10.6 and 10.2

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A. Plot the data for the functions f(x) and g(x) on a grid and connect the points.
labwork [276]

Answer:

  a) see the plots below

  b) f(x) is exponential; g(x) is linear (see below for explanation)

  c) the function values are never equal

Step-by-step explanation:

a) a graph of the two function values is attached

__

b) Adjacent values of f(x) have a common ratio of 3, so f(x) is exponential (with a base of 3). Adjacent values of g(x) have a common difference of 2, so g(x) is linear (with a slope of 2).

__

c) At x ≥ 1, the slope of f(x) is greater than the slope of g(x), and the value of f(x) is greater than the value of g(x), so the curves can never cross for x > 1. Similarly, for x ≤ 0, the slope of f(x) is less than the slope of g(x). Once again, f(0) is greater than g(0), so the curves can never cross.

In the region between x=0 and x=1, f(x) remains greater than g(x). The smallest difference is about 0.73, near x = 0.545, where the slopes of the two functions are equal.

4 0
3 years ago
walt averages 98 miles per hourin 4 races. if each race is 95 miles in lenght, how many miles did walt drive in the race?
Marianna [84]

Answer:

380

Step-by-step explanation:

6 0
3 years ago
Read 2 more answers
The weight of mr nazeer is 7 times that of his son. What's the ratio of their weights?
Mekhanik [1.2K]

Answer:

<h3>7:1</h3>

Step-by-step explanation:

Let the weight of mr nazeer be x

Let the weight of his son be y

If the weight of mr nazeer is 7 times that of his son, then x = 7y

To get the ratio of their weight:

Ratio = weight of father/weight of son

Ratio = 7y/y

Ratio = 7/1

Ratio = 7:1

Hence the ratio of their weights is 7:1

3 0
3 years ago
At Western University the historical mean of scholarship examination scores for freshman applications is 900. A historical popul
vampirchik [111]

Answer:

a) Null Hypothesis: \mu =900

Alternative hypothesis: \mu \neq 900

b) The 95% confidence interval would be given by (910.05;959.95)    

c) Since we confidence interval not ocntains the value of 900 we fail to reject the null hypothesis that the true mean is 900.

d) z=\frac{935 -900}{\frac{180}{\sqrt{200}}}=2.750

Since is a bilateral test the p value is given by:

p_v =2*P(Z>2.750)=0.0059

Step-by-step explanation:

a. State the hypotheses.

On this case we want to check the following system of hypothesis:

Null Hypothesis: \mu =900

Alternative hypothesis: \mu \neq 900

b. What is the 95% confidence interval estimate of the population mean examination  score if a sample of 200 applications provided a sample mean x¯¯¯= 935?

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 means 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.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

\bar X=935 represent the sample mean for the sample  

\mu population mean (variable of interest)

\sigma=180 represent the population standard deviation

n=200 represent the sample size  

The confidence interval for the mean is given by the following formula:

\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}   (1)

In order to calculate the mean and the sample deviation we can use the following formulas:  

\bar X= \sum_{i=1}^n \frac{x_i}{n} (2)  

s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}} (3)  

The mean calculated for this case is \bar X=3278.222

The sample deviation calculated s=97.054

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 table to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that z_{\alpha/2}=1.96

Now we have everything in order to replace into formula (1):

935-1.96\frac{180}{\sqrt{200}}=910.05    

935+1.96\frac{180}{\sqrt{200}}=959.95    

So on this case the 95% confidence interval would be given by (910.05;959.95)    

c. Use the confidence interval to conduct a hypothesis test. Using α= .05, what is your  conclusion?

Since we confidence interval not ocntains the value of 900 we fail to reject the null hypothesis that the true mean is 900.

d. What is the p-value?

The statistic is given by:

z=\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}

If we replace we got:

z=\frac{935 -900}{\frac{180}{\sqrt{200}}}=2.750

Since is a bilateral test the p value is given by:

p_v =2*P(Z>2.750)=0.0059

So then since the p value is less than the significance we can reject the null hypothesis at 5% of significance.

8 0
3 years ago
Kate is constructing an equilateral triangle. She has already used her straightedge to construct the line segment shown. A line
gavmur [86]
<span>Given that Kate is constructing an equilateral triangle and she has already used her straightedge to construct a line segment AB.

What Kate should do for her next step is "</span><span>Place the point of the compass on point A and draw an arc, using AB as the width for the opening of the compass".</span>
4 0
2 years ago
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