A fact family for 9,5,45

Hi can someone check my answers please? thanks, :).

gregori [183]

The 3rd answer is wrong, the answer is 19.
The 5th answer is wrong, the answer is -9.
The 7th answer is wrong, the answer is 8.
The 11th answer is wrong, the answer is 2.
The 12th answer is wrong, the answer is 10.

Hope I could help :)

5 0

3 years ago

Read 2 more answers

A medical researcher wondered if there is a significant difference between the mean birth weight of boy and girl babies. Random

Yuliya22 [10]

Answer:

b) independent samples t-test

$t=\frac{(5.92 -5.74)-(0)}{\sqrt{\frac{1.88^2}{5}}+\frac{1.81^2}{5}}=0.154$

$p_v =2*P(t_{8}>0.154) =0.881$

So with the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the mean of the group 1 (boys) is NOT significantly different than the mean for the group 2 (Girls).

Step-by-step explanation:

The system of hypothesis on this case are:

Null hypothesis: $\mu_1 = \mu_2$

Alternative hypothesis: $\mu_1 \neq \mu_2$

Or equivalently:

Null hypothesis: $\mu_1 - \mu_2 = 0$

Alternative hypothesis: $\mu_1 -\mu_2\neq 0$

Our notation on this case :

$n_1 =5$ represent the sample size for group 1

$n_2 =5$ represent the sample size for group 2

We can calculate the mean and deviation for eaach group with the following formulas:

$\bar X= \frac{\sum_{i=1}^n X_i}{n}$

$s = \sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

$\bar X_1 =5.92$ represent the sample mean for the group 1

$\bar X_2 =5.74$ represent the sample mean for the group 2

$s_1=1.88$ represent the sample standard deviation for group 1

$s_2=1.81$ represent the sample standard deviation for group 2

If we see the alternative hypothesis we see that we are conducting a bilateral test and with independnet samples t test.

b) independent samples t-test

The statistic is given by this formula:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{\sqrt{\frac{s^2_1}{n_1}}+\frac{S^2_2}{n_2}}$

And now we can calculate the statistic:

$t=\frac{(5.92 -5.74)-(0)}{\sqrt{\frac{1.88^2}{5}}+\frac{1.81^2}{5}}=0.154$

The degrees of freedom are given by:

$df=5+5-2=8$

And now we can calculate the p value using the altenative hypothesis:

$p_v =2*P(t_{8}>0.154) =0.881$

So with the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the mean of the group 1 (boys) is NOT significantly different than the mean for the group 2 (Girls).

7 0

4 years ago

Kim is x years old. Jordan is 9 years older than Kim. Five times Jordan’s age is equal to 110.

soldi70 [24.7K]

J=9+x

5J=110

A) 110=5(9+x)

110=45+5x

65=5x

13=x

B) Kim is 13 years old

J=9+x

J=9+13

J=22

C) Jordan is 22 years old

6 0

3 years ago

The school cafeteria sells two types of wraps vegetarian and chicken the vegetarian wrap costs $1.00 and the chicken wrap costs

IRINA_888 [86]

Answer:

35

Step-by-step explanation:

Let's make a system of equations for the vegetarian and chicken wraps; one for the total cost of them and one for the total amount sold.

Vegetarian wraps will be represented by variable v and chicken wraps will be represented by the variable c.

v + 3.40c = 266.20
v + c = 103

Subtract these equations.

2.40c = 163.20

Divide both sides by 2.40.

c = 68

Substitute this value for c into the second equation.

v + (68) = 103

Subtract 68 from both sides.

v = 35

The number of vegetarian wraps sold amounted to 35 in total.

3 0

3 years ago

Read 2 more answers

George wants to purchase a gift for his father for Father’s Day that cost 67.25 if he has already saved 7/8 of the amount how mu

Arlecino [84]

Answer:

$58.84375, rounded ≈ $58.84

Step-by-step explanation:

You can do 67.25 x 7/8 (use a calc if you are lazy) = 58.84375

I'm guessing you don't need to round so I'm going to add both real and rounded answers

3 0

3 years ago