Help me please! It’s number 45.

There are 21 mathematic majors and 129 computer science majors at a college. A) How many ways are there to pick 4 representative

kirza4 [7]

Answer: 1,733,760

Step-by-step explanation:

The number of combinations of selecting m things from n things is given by :-

$^nC_m=\dfrac{n!}{m!(n-m)!}$

Given : There are 21 mathematics majors and 129 computer science majors at a college.

Then, the number of ways to pick 4 representatives, so that 2 are mathematics majors and the other 2 are computer science majors :-

$^{21}C_2\times^{129}C_2\\\\=\dfrac{21!}{2!(21-2)!}\times\dfrac{129!}{2!(129-2)!}\\\\=\dfrac{21\times20\times19!}{2\times19!}\times\dfrac{129\times128\times127!}{2\times127!}\\\\=210\times8256= 1733760$

Hence, the number of ways to pick 4 representatives, so that 2 are mathematics majors and the other 2 are computer science majors =1,733,760

7 0

2 years ago

You are testing the claim that the mean GPA of night students is different from the mean GPA of day students. You sample 30 nigh

lorasvet [3.4K]

Answer:

Step-by-step explanation:

This is a test of 2 independent groups. The population standard deviations are not known. Let μ1 be the mean GPA of night students and μ2 be the mean GPA of day students.

The random variable is μ1 - μ2 = difference in the mean GPA of night students and the mean GPA of day students.

We would set up the hypothesis.

The null hypothesis is

H0 : μ1 = μ2 H0 : μ1 - μ2 = 0

The alternative hypothesis is

H1 : μ1 ≠ μ2 H1 : μ1 - μ2 ≠ 0

Since sample standard deviation is known, we would determine the test statistic by using the t test. The formula is

(x1 - x2)/√(s1²/n1 + s2²/n2)

From the information given,

x1 = 2.35

x2 = 2.58

s1 = 0.46

s2 = 0.47

n1 = 30

n2 = 25

t = (2.35 - 2.58)/√(0.46²/30 + 0.47²/25)

t = - 1.82

The formula for determining the degree of freedom is

df = [s1²/n1 + s2²/n2]²/(1/n1 - 1)(s1²/n1)² + (1/n2 - 1)(s2²/n2)²

df = [0.46²/30 + 0.47²/25]²/[(1/30 - 1)(0.46²/30)² + (1/25 - 1)(0.47²/25)²] = 0.00025247091/0.00000496862

df = 51

We would determine the probability value from the t test calculator. It becomes

p value = 0.075

Alpha = 5% = 0.05

Since alpha, 0.05 < than the p value, 0.075, then we would fail to reject the null hypothesis.

4 0

3 years ago

Pleaseeee helppp i keep getting the wrong so can somebody give me the correct answer

Ne4ueva [31]

Answer: 39.25 miles per gallon.

Step-by-step explanation: To find miles per gallon, divide 314 miles by 8 gallons =

39.25 miles per gallon.

7 0

3 years ago

Read 2 more answers

Suppose that IQ scores in one region are normally distributed with a standard deviation of . Suppose also that exactly of the in

olga55 [171]

Answer: Hello your question is poorly written attached below is the complete question

answer : 101.8

Step-by-step explanation:

Given data :

Standard deviation ( б ) = 14

55% have IQ scores > 100

45% have IQ scores < 100

Determine the mean IQ score for the region

P ( X > x ) =

P ( Z ≥ ( 100 - μ ) / 14 ) = 0.55 also

P ( Z ≤ ( 100 - μ ) / 14 ) = 0.45

using standard normal calculator

100 - μ / 14 = Z₀.₄₅ = - 0.126

resolving the relation above

100 - μ / 14 = - 0.126

μ = 100 - 14 ( -0.126 )

= 101.764 ≈ 101.8

7 0

3 years ago

Although the actual amount varies by season and time of day, the average volume of water that flows over the falls each second

lutik1710 [3]

Given that the average volume of water that flows over the falls each second is $4.8 \times 10^5$ gallons.

There are 3,600 seconds in one hour.

Thus, in one hour, $4.8 \times 10^5\times3600=17280\times10^5=1.728\times10^9$ gallons of water flows over the falls.

Therefore, the amount of water that flows over the falls is $1.728\times10^9$ .

3 0

2 years ago