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3 years ago

Can a smart person help me out? I really need help with these three questions

Mathematics

1 answer:

Illusion [34]3 years ago

4 0

Answer:

1.= 2.4 Hours

2.= 8 miles per hour

3.= 150 miles per hour

Step-by-step explanation:

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Which graph represents x - 1 ≤ 3

MAVERICK [17]

The first graph.

The equation is x - 1 $\leq$ 3
In order to solve it, you need to get x by itself.
Add 1 to both sides. 3+1=4
x $\leq$ 4

Since this is your sign $\leq$ the arrow has to point towards the left, and the circle needs to be colored in.

3 0

3 years ago

Can teachers see how much time you spend on Delta Math?

NARA [144]

Answer:

Yes

Step-by-step explanation:

Short answer- yes.

Long answer- The Student Last Action feature allows teachers to see the last date and time that a student did something on DeltaMath. DeltaMath has several tools that help teachers manage student accounts. Once a student's account is created, a teacher can add the student to one or more classes.

7 0

2 years ago

For the values a=8 which is a leg of a right triangle and value c=19 which is the hypotenuse find the length of the other leg b

FinnZ [79.3K]

C^2=a^2+b^2 we are given the hypotenuse of 19 units and one leg of 8 units so:

19^2=8^2+b^2

361=64+b^2

b^2=297

b=√297

b≈17.2 to the nearest tenth

4 0

3 years ago

Read 2 more answers

If Upper X overbar equals 62, Upper S equals 8, and n equals 36, and assuming that the population is normally distributed, c

marishachu [46]

Answer:

The 99% confidence interval would be given by (58.373;65.627)

We are 99% confident that the true mean for the variable of interest is between 58.373 and 65.627.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X=62$ represent the sample mean

$\mu$ population mean (variable of interest)

s=8 represent the sample standard deviation

n=36 represent the sample size

Part a: Confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=36-1=35$

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,35)".And we see that $t_{\alpha/2}=2.72$