How do you simplify the expression of 7C4 ?

Weinstein, McDermott, and Roediger report that students who were givne questions to be answered while studying new material had

emmainna [20.7K]

<h2>Answer with explanation:</h2>

Let $\mu$ be the population mean.

By considering the given information , we have

Null hypothesis : $H_0: \mu=73.4$

Alternative hypothesis : $H_a: \mu>73.4$

Since alternative hypothesis is right-tailed , so the test is a right-tailed test.

Given : Sample size : n=16 , which is a small sample , so we use t-test.

Sample mean: $\overline{x}=78.3$ ;

Standard deviation: $s=8.4$

Test statistic for population mean:

$t=\dfrac{\overline{x}-\mu}{\dfrac{s}{\sqrt{n}}}$

i.e. $t=\dfrac{78.3-73.4}{\dfrac{8.4}{\sqrt{16}}}\approx2.333$

Using the standard normal distribution table of t , we have

Critical value for $\alpha=0.01$ : $t_{(n-1,\alpha)}=t_{(15,0.01)}=2.602$

Since , the absolute value of t (2.333) is smaller than the critical value of t (2.602) , it means we do not have sufficient evidence to reject the null hypothesis.

Hence, we conclude that we do not have enough evidence to support the claim that answering questions while studying produce significantly higher exam scores.

3 0

3 years ago

write an equation in slope intercept form for a line through the following: through (5,2). with a slope of -2

Veseljchak [2.6K]

Answer:

y = - 2x + 12

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = - 2, thus

y = - 2x + c ← is the partial equation

To find c substitute (5, 2) into the partial equation

2 = - 10 + c ⇒ c = 2 + 10 = 12

y = - 2x + 12 ← equation of line

4 0

3 years ago

Multiply the sum of X and Y by 5 and divide the result by the product of two and a

kvv77 [185]

Answer:

$\frac{5(x+y)}{2a}$ or you could write it as 5(x+Y) ÷ 2a

Step-by-step explanation:

So this is a question that kind of uses spoken words rather than numbers and it involves PEMDAS (if you haven't gotten to PEMDAS yet, don't worry about it, it's ok, it's easy). PEMDAS is simply an acronym for Parenthesis, Exponent, Multiply, Divide, Add, Subtract. Its the order in wwhich you do more complicaterd math problems.

Lets break apart the question:

- We have the sum of x and y, we just write that as x+y

- We have that sum multiplied by 5, we have the sum from the step above, now we'll multiply that by 5. 5(x+y) parenthesis means multiply what is outside with what is inside.

- We have the product (multiply) of 2 and a, 2 times a = 2a.

- We divide the x, y, and 5 term with the 2, a term. Take the first part 5(x+y) and divide it by the second part 2a.

6 0

3 years ago

Is 15 over 45 equivalent to 45 over 135

faltersainse [42]

Yes, in simplest form, both fractions are 1/3 (one over three)

3 0

3 years ago

50 US states for the namethat start with the letter W what percent of US states have the names that start with the letter W

Vanyuwa [196]

Washington, West Virginia, Wisconsin, Wyoming
Four states out of 50
4 / 50 * 100 = 8 per cent.

3 0

3 years ago