400 is 1/10 of what number

On a coordinate grid, point A is at (−2.0, −3.4) and point B is at (2.0, −3.4). Point B is a reflection of point A across the __

blondinia [14]

Answer:

y.

Step-by-step explanation:

When you reflect a point across the x-axis the sign of the y value changes. In the case of reflection across the y-axis the sign of the x value changes. So, for the point A(-2,-3.4) after the reflection the point B(2,-3.4) has the x value with different sign, so is a reflection over the y-axis.

8 0

3 years ago

Given that f(x) = x2 + x and g(x) = 3x + 1, find the value of g(f(-2)).

Evgen [1.6K]

Answer:

Step-by-step explanation:

$f(x) = x^2 + x\\g(x) = 3x + 1\\\\g(f(-2)) = ?\\f(-2) =?\\$

To find f(-2) , Substitute -2 for x in the given equation ;

$f(-2)= (-2)^2 +(-2)\\f(-2) = 4-2\\f(-2) = 2$

To find g(f(-2)) ;

$g(f(-2))\\f(-2) =2\\\\= g(f(-2)) = g(2)\\$

To find g(2) , substitute 2 for x in the given equation

$g(x) = 3x+1\\g(2) = 3(2)+1\\\\g(f(-2)) = 6+1\\\\g(f(-2))=7$

5 0

3 years ago

The diameters of bearings used in an aircraft landing gear assembly have a standard deviation of ???? = 0.0020 cm. A random samp

vovikov84 [41]

Answer:

(a) We conclude after testing that mean diameter is 8.2500 cm.

(b) P-value of test = 2 x 0.0005% = 1 x $10^{-5}$ .

(c) 95% confidence interval on the mean diameter = [8.2525 , 8.2545]

Step-by-step explanation:

We are given with the population standard deviation, $\sigma$ = 0.0020 cm

Sample Mean, Xbar = 8.2535 cm and Sample size, n = 15

(a) Let Null Hypothesis, $H_0$ : Mean Diameter, $\mu$ = 8.2500 cm

Alternate Hypothesis, $H_1$ : Mean Diameter, $\mu$ $\neq$ 8.2500 cm{Given two sided}

So, Test Statistics for testing this hypothesis is given by;

$\frac{Xbar-\mu}{\frac{\sigma}{\sqrt{n} } }$ follows Standard Normal distribution

After putting each value, Test Statistics = $\frac{8.2535-8.2500}{\frac{0.0020}{\sqrt{15} } }$ = 6.778

Now we are given with the level of significance of 5% and at this level of significance our z score has a value of 1.96 as it is two sided alternative.

Since our test statistics does not lie in the rejection region{value smaller than 1.96} as 6.778>1.96 so we have sufficient evidence to accept null hypothesis and conclude that the mean diameter is 8.2500 cm.

(b) P-value is the exact % where test statistics lie.

For calculating P-value , our test statistics has a value of 6.778

So, P(Z > 6.778) = Since in the Z table the highest value for test statistics is given as 4.4172 and our test statistics has value higher than this so we conclude that P - value is smaller than 2 x 0.0005% { Here 2 is multiplied with the % value of 4.4172 because of two sided alternative hypothesis}

Hence P-value of test = 2 x 0.0005% = 1 x $10^{-5}$ .

(c) For constructing Two-sided confidence interval we know that:

Probability(-1.96 < N(0,1) < 1.96) = 0.95 { This indicates that at 5% level of significance our Z score will lie between area of -1.96 to 1.96.

P(-1.96 < $\frac{Xbar-\mu}{\frac{\sigma}{\sqrt{n} } }$ < 1.96) = 0.95

P( $-1.96\frac{\sigma}{\sqrt{n} }$ < $Xbar - \mu$ < $1.96\frac{\sigma}{\sqrt{n} }$ ) = 0.95

P( $-Xbar-1.96\frac{\sigma}{\sqrt{n} }$ < $-\mu$ < $1.96\frac{\sigma}{\sqrt{n} }-Xbar$ ) = 0.95

P( $Xbar-1.96\frac{\sigma}{\sqrt{n} }$ < $\mu$ < $Xbar+1.96\frac{\sigma}{\sqrt{n} }$ ) = 0.95

So, 95% confidence interval for $\mu$ = [ $Xbar-1.96\frac{\sigma}{\sqrt{n} }$ , $Xbar+1.96\frac{\sigma}{\sqrt{n} }$ ]

= [ $8.2535-1.96\frac{0.0020}{\sqrt{15} }$ , $8.2535+1.96\frac{0.0020}{\sqrt{15} }$ ]

= [8.2525 , 8.2545]

Here $\mu$ = mean diameter.

Therefore, 95% two-sided confidence interval on the mean diameter

= [8.2525 , 8.2545] .

6 0

3 years ago

Read 2 more answers

Ellen drove 220 miles in 3.5hours. To the nearest tenth, find Ellen's average speed in miles per hours

34kurt

divide total miles by time:

220 / 3.5 = 62.857

rounded to nearest tenth = 62.9 miles per hour

5 0

3 years ago

Explain the process for finding the product of two integers

mafiozo [28]

Rule 1: The product of a positive integer and a negative integer is a negative integer. Rule 2: The product of two negative integers or two positive integers is a positive integer

4 0

3 years ago