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3 years ago

John throws a ball upward at a rate of 22 meters per second from an

Mathematics

1 answer:

nordsb [41]3 years ago

8 0

Answer:

1.5 seconds

Step-by-step explanation:

The height equation is supposed to be ...

h(t) = -16t^2 +22t +3

We want to find the positive value of t where h(t) = 0.

0 = -16t^2 +24t -2t +3 . . . . facilitate factoring

0 = -8t(2t -3) -1(2t -3) . . . . . factor by pairs

0 = -(8t +1)(2t -3) . . . . . . . . complete the factoring

The solutions to this are ...

t = -1/8, 3/2

The ball will reach the ground in 1.5 seconds.

You might be interested in

What is the probability of randomly drawing an odd number between 24 and 33?

Studentka2010 [4]

Write out the numbers between 24 and 33: {24, 25, 26, 27, 28, 29, 30, 31, 32, 33}

How many numbers have we here? 10.

How many of these numbers are odd? {25, 27, 29, 31, 33}

Strictly speaking, "between 24 and 33" does not include {24, 33}.

Thus, the odd numbers between 24 and 33 are {25, 27, 29, 31}

The chances of drawing an odd number between 24 and 33 are then 4 / 10.

If, however, we omit the endpoints 24 and 33, then there are 8 numbers between 24 and 33: {25, 27, 29, 31}

and the odds of choosing an odd number from these eight numbers is 4/8, or 1/2, or 0.50.

6 0

3 years ago

An SRS of 350 high school seniors gained an average of x¯=21 points in their second attempt at the SAT Mathematics exam. Assume

Lynna [10]

Answer:

a) $21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

b) $ME=2.58\frac{52}{\sqrt{350}}=7.17$

c) $ME=2.58\frac{52}{\sqrt{100}}=13.42$

d) D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

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".

Part a

$\bar X=21$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=52$ represent the population standard deviation

n=350 represent the sample size

99% confidence interval

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

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

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: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$