Evaluate the expression 4x2+3y for x = 5 and y =6.

For each of the finite geometric series given below, indicate the number of terms in the sum and find the sum. For the value of

kotykmax [81]

Answer:

Number of term N = 9

Value of Sum = 0.186

Step-by-step explanation:

From the given information:

Number of term N = $3 (0.5)^{5} + 3 (0.5)^{6} + 3 (0.5)^{7} + \cdots + 3 (0.5)^{13}$

Number of term N = $3 (0.5)^{5} + 3 (0.5)^{6} + 3 (0.5)^{7} +3 (0.5)^{8}+3 (0.5)^{9} +3 (0.5)^{10} +3 (0.5)^{11}+3 (0.5)^{12}+ 3 (0.5)^{13}$

Number of term N = 9

The Value of the sum can be determined by using the expression for geometric series:

$\sum \limits ^n_{k=m}ar^k =\dfrac{a(r^m-r^{n+1})}{1-r}$

here;

m = 5

n = 9

r = 0.5

Then:

$\sum \limits ^n_{k=m}ar^k =\dfrac{3(0.5^5-0.5^{9+1})}{1-0.5}$

$\sum \limits ^n_{k=m}ar^k =\dfrac{3(0.03125-0.5^{10})}{0.5}$

$\sum \limits ^n_{k=m}ar^k =\dfrac{(0.09375-9.765625*10^{-4})}{0.5}$

$\sum \limits ^n_{k=m}ar^k =0.186$

6 0

3 years ago

A student was asked to find a 90% confidence interval for the proportion of students who take notes using data from a random sam

Scorpion4ik [409]

Answer:

After use the formula we got the following result for the 90% confidence interval (0.13 <p<0.34)

And the conclusion for this case would be:

e. With 90% confidence, the proportion of all students who take notes is between 0.13 and 0.34.

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".

Description in words of the parameter p

$p$ represent the real population proportion of students who take notes

$\hat p$ represent the estimated proportion of students who take notes

n is the sample size required

$z_{\alpha/2}$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Numerical estimate for p

In order to estimate a proportion we use this formula:

$\hat p =\frac{X}{n}$ where X represent the number of people with a characteristic and n the total sample size selected.

Confidence interval

The confidence interval for a proportion is given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 90% confidence interval the value of $\alpha=1-0.90=0.1$ and $\alpha/2=0.05$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.64$

After use the formula we got the following result for the 90% confidence interval (0.13 <p<0.34)

And the conclusion for this case would be:

e. With 90% confidence, the proportion of all students who take notes is between 0.13 and 0.34.

6 0

2 years ago

Based on the graph which statement is true

Dahasolnce [82]

Answer:

D. He needs 6 cups of flour for 3 batches

6 0

3 years ago

Sophia exchanged 1,000 US dollars for the south African currency. the exchange rate was 7.15 rand to $1.00.

mel-nik [20]

1 / 7.15 = 1000 / x......$ 1 to 7.15 rand = $ 1000 to x rand
cross multiply because this is a proportion
(1)(x) = (7.15)(1000)
x = 7150 <=== Sophia got 7150 rand

5 0

3 years ago

-7c+9=c+1 <br> If you could also show how you did it i would appreciate it

Step2247 [10]

-7c+9=c+1 (subtract c on both sides)
-8c+9=1 (subtract 9 on both sides)
-8c=-8 (divide by -8 on both sides to get c by its self)
c=1
your answer is 1.

5 0

2 years ago

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