What is the surface area, in square centimeter, of the square pyramid?

A researcher is conducting a study of charitable donations by surveying a simple random sample of households in a certain city.

nirvana33 [79]

Answer:

H0: p ≤ 0.50

Ha: p > 0.50

Step-by-step explanation:

The null hypothesis (H0) tries to show that no significant variation exists between variables or that a single variable is no different than its mean. While an alternative Hypothesis (Ha) attempt to prove that a new theory is true rather than the old one. That a variable is significantly different from the mean.

For the case above;

Let p represent the proportion of households in the city that gave a charitable donation in the past year

The null hypothesis is that the proportion of households in the city that gave a charitable donation in the past year is not more that 0.50

H0: p ≤ 0.50

The alternative hypothesis is that the proportion of households in the city that gave a charitable donation in the past year is more that 0.50

Ha: p > 0.50

7 0

3 years ago

What is the volume of the cube in cubic feet? please help

motikmotik

Answer:

512

Step-by-step explanation:

since its a cube, all the side lengths are even, so its just 8^3 or 8*8*8

8 0

3 years ago

The degenerative disease osteoarthritis most frequently affects weight-bearing joints such as the knee. Two random samples from

Vinvika [58]

Answer:

$t=\frac{(810-770)-0}{\sqrt{\frac{67^2}{13}+\frac{56^2}{19}}}}=1.771$

$df=n_1 +n_2 -2=13+19-2=30$

Since is a right tailed test the p value would be:

$p_v =P(t_{30}>1.771)=0.0434$

Comparing the p value with the significance level $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the mean for group 1 is significantly higher than the mean for the group 2

Step-by-step explanation:

Data given

$\bar X_{1}=810$ represent the mean for sample 1

$\bar X_{2}=770$ represent the mean for sample 2

$s_{1}=67$ represent the sample standard deviation for 1

$s_{2}=56$ represent the sample standard deviation for 2

$n_{1}=13$ sample size for the group 2

$n_{2}=19$ sample size for the group 2

$\alpha=0.05$ Significance level provided

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the mean for category 1 is higher than the mean for category 2, the system of hypothesis would be:

Null hypothesis: $\mu_{1}-\mu_{2}\leq 0$

Alternative hypothesis: $\mu_{1} - \mu_{2}> 0$

We don't have the population standard deviation's, so for this case is better apply a t test to compare means, and the statistic is given by:

$t=\frac{(\bar X_{1}-\bar X_{2})-\Delta}{\sqrt{\frac{\sigma^2_{1}}{n_{1}}+\frac{\sigma^2_{2}}{n_{2}}}}$ (1)

And the degrees of freedom are given by $df=n_1 +n_2 -2=13+19-2=30$

t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

With the info given we can replace in formula (1) like this:

$t=\frac{(810-770)-0}{\sqrt{\frac{67^2}{13}+\frac{56^2}{19}}}}=1.771$

P value

Since is a right tailed test the p value would be:

$p_v =P(t_{30}>1.771)=0.0434$

Comparing the p value with the significance level $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the mean for group 1 is significantly higher than the mean for the group 2

4 0

3 years ago

I need help with linear regression

frutty [35]

Answer:

<em>In statistics, linear regression is a linear approach to modelling the relationship between a scalar response (or dependent variable) and one or more explanatory variables (or independent variables). The case of one explanatory variable is called simple linear regression. For more than one explanatory variable, the process is called multiple linear regression. This term is distinct from multivariate linear regression, where multiple correlated dependent variables are predicted, rather than a single scalar variable.</em>

6 0

3 years ago

Whats -4 1/5 times 1/3 ?

tamaranim1 [39]

Answer: -7/5

Step-by-step explanation:

-4(1/5)⋅(1/3)

Convert -4(1/5) to an improper fraction.

A mixed number is an addition of its whole and fractional parts.

− (4 +1/5) ⋅(1/3)

Add 4 and 1/5

-21/5 ⋅ 1/3

Cancel the common factor of 3.

Move the leading negative in − 21 /5 into the numerator.

−21/5 ⋅ 1/3

Factor 3 out of −21.

3 (−7)/5 ⋅ 3 /1

Cancel the common factor.

Rewrite the expression.

−7 /5

5 0

3 years ago

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