Pliz answer this question

A sample of 300 urban adult residents of a particular state revealed 65 who favored increasing the highway speed limit from 55 t

forsale [732]

Answer and explanation:

Null hypothesis(H0) says sentiment for increasing speed limit in the two populations is the same

Alternative hypothesis(Ha) says sentiment for increasing speed limit in the two populations is different

Where p1 is the first population proportion =65/297= 0.22

And p2 is the second population proportion = 78/189= 0.41

P= p1+p2/n1+n2= 65+78/297+189= 0.29

Hence H0= p1-p2=0

Ha=p1-p2≠0

Test statistic= p1-p2/√p(1-p) (1/n1+1/n2)

= 0.22-0.41/√0.29(1-0.29)(1/297+1/189)

= -4.49

Critical value at 95% significance level= 1.96( from tables)

We therefore reject null hypothesis as critical value is greater than test statistic

Therefore the sentiment for increasing speed limit in the two populations is different

b. at proportions of 0.24 and 0.40 for p1 and p2 respectively

Test statistic = 0.24-0.40/0.29(1-0.29)(1/297+1/189)

= -3.78

P value is 0.0002 at 0.05 significance level

Hence probability =0.4998

7 0

3 years ago

3. A fast food joint sells 5 boxes of chicken nuggets for $33.90. Another fast food joint sells 4 boxe:

mrs_skeptik [129]

33.90/5= 6.78 or 26.88/4= 6.72. The 4 boxes of chicken fingers has the cheaper unit price

3 0

3 years ago

3x^2-192=0<br><img src="https://tex.z-dn.net/?f=3%20%7Bx%7D%5E%7B2%7D%20%20-%20192%20%3D%200" id="TexFormula1" title="3 {x}^{2}

Murljashka [212]

$3x^2-192=0$
$3x^2=192$
$x^2=\frac{192}{3}$
$x=\pm \sqrt{64}$
$x=\pm 8$

x=-8 and x=8 are the solutions

5 0

2 years ago

Read 2 more answers

The probability that your call to a service line is answered in less than 30 seconds is 0.75. Assume that your calls are indepen

vfiekz [6]

Answer:

a) 0.2581

b) 0.4148

c) 17

Step-by-step explanation:

For each call, there are only two possible outcomes. Either they are answered in less than 30 seconds. Or they are not. The probabilities for each call are independent. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

In this problem we have that:

$p = 0.75$

a. If you call 12 times, what is the probability that exactly 9 of your calls are answered within 30 seconds? Round your answer to four decimal places (e.g. 98.7654).

This is $P(X = 9)$ when $n = 12$ . So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 9) = C_{12,9}.(0.75)^{9}.(0.25)^{3} = 0.2581$

b. If you call 20 times, what is the probability that at least 16 calls are answered in less than 30 seconds? Round your answer to four decimal places (e.g. 98.7654).

This is $P(X \geq 16)$ when $n = 20$