In the polynomial below, what number should replace the question mark to produce a difference of squares?

fenix001 [56]

Add how many days points from lowest up too but not including 82. there are 12 of them third option, 12

8 0

3 years ago

A student reads that a 95% confidence interval for the mean SAT math score of California high school seniors is 452 to 470. Aske

mestny [16]

Yes he is correct due to facts stated

5 0

3 years ago

Liang has a goal of walking at least 18 miles. She walks at a rate of 4 miles per hour. Which inequality can liang use to find h

frozen [14]

Answer:

t ≤ 4.5

Step-by-step explanation:

We are told that the goal is to walk at least 18 miles

She walks at a rate of 4 miles per hour, speed is 4mph

Required

the inequality for the time taken to walk the distance and the said speed

Step two:

we know that

speed= distance/time

time=distance/speed

substitute

time= 18/4

time= 4.5 hours

Time≤ 4.5 hours

3 0

3 years ago

Enter the distance between points (4, -7) and (-5,5) on the coordinate plane.<br> units

Aloiza [94]

Answer:

piontttttsssssssss

Step-by-step explanation:

3 0

4 years ago

An experiment was conducted to compare the use of iPads versus regular textbooks in teaching algebra to two classes of middle sc

lakkis [162]

Answer:

Step-by-step explanation:

Hello!

The objective is to determine if there is any difference between using iPads vs textbooks in teaching algebra.

Two middle school classes were selected, to eliminate any other source of variation, the same teacher taught both classes, and the materials were provided by the same author and publisher. After a month 10 students of each class were randomly selected and tested, their test scores were recorded:

X₁: test scores of students that used iPads to study.

n₁= 10

X[bar]₁= 86.8

S₁= 8.97

X₂: test scores of students that used regular textbooks to study.

n₂= 10

X[bar]₂= 79.5

S₂= 10.8

a.

H₀: μ₁=μ₂

H₁: μ₁≠μ₂

α:0.05

Assuming that both variables are normally distributed and the population variances are equal, the statistic to use is a Student t for two independent samples with pooled sample variance:

$t_{H_0}= \frac{(X[bar]_1-X[bar]_2)-(Mu_1-Mu_2)}{Sa*\sqrt{\frac{1}{n_1} +\frac{1}{n_2} } }$

$Sa^2= \frac{(n_1-1)S^2_1+(n_2-1)S^2_2}{n_1+n_2-2}$

$Sa^2= \frac{9*80.4609+9*116.64}{10+10-2} = 98.55$

Sa= 9.93

$t_{H_0}= \frac{86.8-79.5}{9.93\sqrt{\frac{1}{10} +\frac{1}{10} } } = 1.64$

p-value: 0.118364

The p-value is greater than the significance level so the decision is to not reject the null hypothesis. This means that there is no significant evidence between the scores of the two groups.

b.

95% CI

(X[bar]-X[bar])± $t_{n_1+n_2-2;1-\alpha /2}$ * $Sa\sqrt{\frac{1}{n_1} +\frac{1}{n_2} }$

$t_{n_1+n_2-2;1-\alpha /2}= t_{18;1.975}= 2.101$

(86.8-79.5)±2.101*(9.93 $\sqrt{\frac{1}{10} +\frac{1}{10} }$ )

[-2.03; 16.63]

With a 95% confidence level, you'd expect that the interval [-2.03; 16.63] would contain the difference between the mean scores of the two classes.

c.

Considering that the null hypothesis wasn't rejected and that at the same level the confidence interval includes the zero, we can affirm that the format of the teaching materials, digital or regular textbooks, has no significant effect on the scores of the students.

I hope it helps!

3 0

4 years ago