I am going to ask 4 questions im sorry...

A random sample of 100 people from City A has an average IQ of 120 with a SD of 18. Independently of this, a random sample of 15

Sloan [31]

Answer:

$z=\frac{(120-116)-0}{\sqrt{\frac{18^2}{100}+\frac{15^2}{150}}}}=1.837$

$p_v =P(z>1.837)=1-P(Z$

Comparing the p value with a significance level for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that the average IQ on city A is signficantly higher than city B at 5% of singificance.

Step-by-step explanation:

$\bar X_{A}=120$ represent the mean for sample 1

$\bar X_{B}=116$ represent the mean for sample 2

$s_{A}=18$ represent the sample standard deviation for 1

$s_{B}=15$ represent the sample standard deviation for 2

$n_{A}=100$ sample size for the group 2

$n_{B}=150$ sample size for the group 2

$\alpha$ Significance level provided

z would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if residents of City A smarter on average, the system of hypothesis would be:

Null hypothesis: $\mu_{A}-\mu_{B}\leq 0$

Alternative hypothesis: $\mu_{A} - \mu_{B}> 0$

We don't have the population standard deviation's, but the sample sizes are large enough we can apply a z test to compare means, and the statistic is given by:

$z=\frac{(\bar X_{A}-\bar X_{B})-\Delta}{\sqrt{\frac{s^2_{A}}{n_{A}}+\frac{s^2_{B}}{n_{B}}}}$ (1)

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

With the info given we can replace in formula (1) like this:

$z=\frac{(120-116)-0}{\sqrt{\frac{18^2}{100}+\frac{15^2}{150}}}}=1.837$

P value

Since is a one right tailed test the p value would be:

$p_v =P(z>1.837)=1-P(Z$

Comparing the p value with a significance level for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that the average IQ on city A is signficantly higher than city B at 5% of singificance.

5 0

3 years ago

Long Questions

docker41 [41]

484 dollars ...........

4 0

3 years ago

What is 25/30 in simplest form?

Triss [41]

You divide the numbers by 5 so the fraction will be 5/6

5 0

3 years ago

HELP ME SOMEONE PLSSSSSSSS ANSWER THE QUESTIONS. AND PLSS PLS EXPLAIN. ANSWER ALL OF THEM.

MatroZZZ [7]

Answer: Check out the attached diagram below for the filled out table.

Explanation:

A) This is correct. You basically stick a minus sign out front to reflect over the x axis (aka the line y = 0).
B) Replacing x with x+2 will shift the graph 2 units to the left. Adding on 3 at the end will shift it up 3 units.
C) A vertical stretch, aka vertical dilation, makes the graph taller than it already is. In this case, we want to stretch it to make it twice as tall. That explains the 2 out front. The negative is there to reflect over the x axis.
D) The -2 is to apply a dilation of 2 and do a reflection. The +6 is so ensure that the vertex arrives at the proper location (0,6) so that we reflect over y = 3.
E) This is similar to part B. Replacing x with x-3 shifts the graph 3 units to the right. We subtract off 2 at the end to shift the graph down 2 units. The 1/2 out front applies the dilation, which in this case is a vertical compression by a factor of 2.
F) A vertical compression by a factor of 4 is the same as dilating by a factor of 1/4. So we'll multiply f(x) by 1/4.
G) Similar to part F, but we'll be using the scale factor 4 this time.

5 0

3 years ago

Read 2 more answers

If 70% is £14,what is the full cost

Sindrei [870]

The answer would be £20, you would turn this into a proportion and doing that you'd have 70/100=14/x(x being the full cost) then you cross multiply and doing so you get 1400=70x and 1400 divided by 70 equals 20, so your answer is £20

5 0

3 years ago