If 12 + 3 = 15, what other addition fact and what two subtraction facts

What is the answer in substiution y=2x-9 and y=3

ale4655 [162]

Answer:

x= -6

Step-by-step explanation:

7 0

1 year ago

Read 2 more answers

If (1/a)+(1/b)=10 what is the value of a+b?

Goshia [24]

B) 2/5

I think, if a and b are the same (coz then they would both equal 0.2)

3 0

3 years ago

An automobile company wants to determine the average amount of time it takes a machine to assemble a car. A sample of 40 times y

aksik [14]

Answer:

A 98% confidence interval for the mean assembly time is [21.34, 26.49] .

Step-by-step explanation:

We are given that a sample of 40 times yielded an average time of 23.92 minutes, with a sample standard deviation of 6.72 minutes.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample average time = 23.92 minutes

s = sample standard deviation = 6.72 minutes

n = sample of times = 40

$\mu$ = population mean assembly time

Here for constructing a 98% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.

So, a 98% confidence interval for the population mean, $\mu$ is;

P(-2.426 < $t_3_9$ < 2.426) = 0.98 {As the critical value of z at 1% level

of significance are -2.426 & 2.426}

P(-2.426 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 2.426) = 0.98

P( $-2.426 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $2.426 \times {\frac{s}{\sqrt{n} } }$ ) = 0.98

P( $\bar X-2.426 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.426 \times {\frac{s}{\sqrt{n} } }$ ) = 0.98

98% confidence interval for $\mu$ = [ $\bar X-2.426 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+2.426 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $23.92-2.426 \times {\frac{6.72}{\sqrt{40} } }$ , $23.92+2.426 \times {\frac{6.72}{\sqrt{40} } }$ ]

= [21.34, 26.49]

Therefore, a 98% confidence interval for the mean assembly time is [21.34, 26.49] .

7 0

3 years ago

Please answer I’ll rate brainlyest

12345 [234]

Answer:

$5P3*6C4=60*15=900$

Step-by-step explanation:

$5P3$ refers to the permutations of 5 items taken 3 at a time. To evaluate this, we use factorials as follows;

$5P3=\frac{5!}{(5-3)!}$

The factorial of an integer n is evaluated as;

$n!=n*(n-1)*(n-2)*(n-3).......3*2*1$

Using this concept, the above expression can now be simplified as follows;

$5P3=\frac{5!}{2!}=\frac{5*4*3*2!}{2!}=5*4*3=60$

Therefore, the permutations of 5 items taken 3 at a time is 60.

The next expression, $6C4$ refers to the combinations of 6 items taken 4 at a time. The simplification utilizes similar concepts of permutations since we shall be involving factorials;

$6C4=\frac{6!}{4!(6-4)!}=\frac{6!}{4!*2!}=\frac{6*5*4!}{4!*2*1}=\frac{6*5}{2*1}=15$

Therefore, the combinations of 6 items taken 4 at a time is 15.

The final step is to evaluate the product;

$5P3*6C4=60*15=900$

3 0

3 years ago

Need help in less than 5 minutes brainliest to the first/most helpful answer!! Need it speedy!!!!

Sonbull [250]

Answer:

1.) True

2.) False

3.) True

4.) True

6 0

2 years ago