I don’t know what they expect me to put but help

What is the sum or difference? 3x^8 + 7x^8

posledela

Answer:

10x^8 is the sum

Step-by-step explanation:

7 0

3 years ago

if a sample size 40 is drawn from the population that has mean 276 and a variance of 81, what is the probability that the mean o

lapo4ka [179]

Answer:

The probability is 0.017429

Step-by-step explanation:

We start by calculating the z-score

Mathematically;

z-score = (x-mean)/SD/√n

In this case;

x = 273

mean = 276

SD = √(variance) = √81 = 9

n = 40

Substituting these values into the z-score formula, we have that;

z = (273-276)/9/√40

z = -2.11

So we proceed to get the probability

the probability in this case is;

P( z < -2.11)

We can use the normal distribution table for this

Our answer will be

P( z < -2.11) = 0.017429

4 0

3 years ago

Jack and Jill both start at point A. They each walk in a straight line at an angle of 105° to each other. After 45 minutes Jack

ASHA 777 [7]

Answer: The distance between them is 8.38 km

Step-by-step explanation:

Let's suppose both of them start at the point (0km, 0km), and that Jack walks along the positive x-axis, then Jill walks at an angle of 105° measured from the positive x-axis.

After 45 minutes, jack has walked 4.5km, then if his initial position was (0 km, 0 km)

Then his new position will be (4.5km, 0km)

Jill has walked 6km, but we need to write this in rectangular components.

We can think in this as a triangle rectangle, then the components will be:

x-component = 6 km*cos(105°) = -1.55 km

y-component = 6km*sin(105°) = 5.80 km

Then the new position of Jill is ( -1.55km, 5.80km)

Now, we know that the distance between two points (a, b) and (c, d) is:

Distance = √( (a - c)^2 + (b - d)^2)

Then the distance between Jill and Jack will be equal to the distance between ( -1.55km, 5.80km) and (4.5km, 0km)

This is:

Distance = √( (-1.55km - 4.5km)^2 + (5.80km - 0km)^2)

Distance = 8.38 km

This means that they are 8.38km apart.

4 0

3 years ago

Whats the selling price if the cost is $99.50 and the markup is 95%?

DerKrebs [107]

99.50 * 1.95 = $194.03

3 0

3 years ago

Test the claim that the proportion of people who own cats is significantly different than 90% at the 0.1 significance level.

VikaD [51]

Answer:

1. H0 : p = 0.9

H1 : p ≠ 0.9

2. The test is two tailed.

3. Reject the null hypothesis

Step-by-step explanation:

We are given that we have to test the claim that the proportion of people who own cats is significantly different than 90% at the 0.1 significance level.

So, Null Hypothesis, $H_0$ : p = 0.90

Alternate Hypothesis, $H_1$ : p $\neq$ 0.9

Here, the test is two tailed because we have given that to test the claim that the proportion of people who own cats is significantly different than 90% which means it can be less than 0.90 or more than 0.90.

Now, test statistics is given by;

$\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ~ N(0,1) , where, n = sample size = 100

$\hat p$ = 0.94 (given)

So, Test statistics = $\frac{0.94-0.90}{\sqrt{\frac{0.94(1-0.94)}{100} } }$ = 1.68

Now, P-value = P(Z > 1.68) = 1 - P(Z <= 1.68)

= 1 - 0.95352 = 0.0465 ≈ 0.05 or 5%

Now, our decision rule is that;

If p-value < significance level ⇒ Reject null hypothesis

If p-value > significance level ⇒ Accept null hypothesis

Since, here p-value is less than significance level as 0.05 < 0.1, so we have sufficient evidence to reject null hypothesis.

Therefore, we conclude that proportion of people who own cats is significantly different than 90%.

8 0

3 years ago