-(-10)=?<br> Please help me with this equation!!

If it takes John 10 hours to paint the fence, how long will it take John and his two friends to do the job if they work at the s

VMariaS [17]

Answer:

look in picture below :)

3 0

3 years ago

The NCAA is interested in estimating the difference in mean number of daily training hours for men and women athletes on college

hammer [34]

Answer:

$s^2_p = \frac{9*0.3^2 +9*0.4^2}{10+10-2}=0.125$

$s_p =\sqrt{0.125}=0.354$

$(2.7 -2.4) - 2.1*0.354\sqrt{\frac{1}{10}+\frac{1}{10}}=-0.032$

$(2.7 -2.4)+ 2.1*0.354\sqrt{\frac{1}{10}+\frac{1}{10}}=0.632$

Step-by-step explanation:

Previous concepts

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".

Data given

$\bar X_M = 2.7$ represent the sample mean for men

$\bar X_F = 2.4$ represent the sample mean for women

$s_M = 0.3$ represent the sample deviation for men

$s_F = 0.4$ represent the sample deviation for women

$n_M = 10$ sample size of male

$n_F =10$ sample size of women

The confidence interval is given by:

$(\bar X_M -\bar X_F) \pm t_{\alpha/2} S_p \sqrt{\frac{1}{n_M}+\frac{1}{n_F}}$ (1)

The polled variance can be calculated with this formula:

$s^2_p = \frac{9*0.3^2 +9*0.4^2}{10+10-2}=0.125$

$s_p =\sqrt{0.125}=0.354$

For a confidence of 95% the value for the significance is $\alpha=1-0.95=0.05$ and $\alpha/2 = 0.025$ , the degrees of freedom are given by:

$df = n_M + n_F -2= 10+10-2=18$

And the critical value can be calculated with the following formula in excel: "=T.INV(1-0.025,18)" and we got $t_{\alpha/2}=2.1$

Now we can replace into the confidence interval:

$(2.7 -2.4) - 2.1*0.354\sqrt{\frac{1}{10}+\frac{1}{10}}=-0.032$

$(2.7 -2.4)+ 2.1*0.354\sqrt{\frac{1}{10}+\frac{1}{10}}=0.632$

6 0

3 years ago

Whats 5+5 plz answer

Lisa [10]

Answer:10

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

(2x+ 2) +(3 - 5x) 4.) (3x3 - 4x4) +(2x + 5x4)

HACTEHA [7]

Answer:

1. $\boxed{ \bold{ \sf{ - 3x + 5}}}$

2. $\boxed{ \bold{ \sf{ {x}^{4} + 3 {x}^{3} + 2x}}}$

Step-by-step explanation:

1. $\sf{(2x + 2) + (3 - 5x)}$

When there is a ( + ) in front of expression in parentheses , the expression remains the same.

⇒ $\sf{2x + 2 + 3 - 5x}$

Collect like terms

⇒ $\sf{ - 3x + 2 + 3}$

Add the numbers

⇒ $\sf{ - 3x + 5}$

2. $\sf{( {3x}^{3} - 4 {x}^{4} ) + (2x + 5 {x}^{4}) }$

When there is a ( + ) in front of expression in parantheses , the expression remains the same

⇒ $\sf{3 {x}^{3} - 4 {x}^{4} + 2x + {5x}^{4} }$

Collect like terms

⇒ $\sf{ {x}^{4} + 3 {x}^{3} + 2x}$

Hope I helped!

Best regards!!

3 0

3 years ago

A credit card issuer offers an APR of 15.83% and compounds interest daily.

Romashka-Z-Leto [24]

Answer:

C. Its APR, because it's less than its effective interest rate.

Step-by-step explanation:

The interest rate determines the money you must pay on the outstanding balance on the credit card.

The credit card company would advertise the lowest numbers it could truthfully use.

The APR is 15.83 %.

The formula for the effective interest rate is

$i = \left (1 + \dfrac{r}{n} \right )^{n} - 1$

where the interest rates are expressed as decimals.

If the APR is 15.83% and the interest is compounded daily,

$\begin{array}{rcl}i & = & \left (1 + \dfrac{0.1583}{365} \right )^{365} -1\\\\ & = & (1 + 0.0004337)^{365} -1\\ & = & (1.0004337)^{365} -1\\ & = & 1.1715 - 1\\& = & 0.1715\\& = & 17.15 \%\\\end{array}\\\text{The effective interest rate is $\mathbf{17.15 \%}$}$

The APR is less than the effective interest rate, so that's what the company would advertise.

4 0

3 years ago

-(-10)=? Please help me with this equation!!