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3 years ago

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Test scores for a Statistics class have a mean of 78 with a standard deviation of 6. Suppose a student gets an 81 on that test.

What is the z-score for that grade?

1 answer:

Ostrovityanka [42]3 years ago

5 0

Answer:

0.3209

in case you dont know A z-score tells you if the distribution it comes from is normal.

Step-by-step explanation:

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In Quebec, 90 percent of the population subscribes to the Roman Catholic religion. In a random sample of eight Quebecois, find t

AysviL [449]

Answer:

Probability that the sample contains at least five Roman Catholics = 0.995 .

Step-by-step explanation:

We are given that In Quebec, 90 percent of the population subscribes to the Roman Catholic religion.

The Binomial distribution probability is given by;

P(X = r) = $\binom{n}{r}p^{r}(1-p)^{n-r}$ for x = 0,1,2,3,.......

Here, n = number of trials which is 8 in our case

r = no. of success which is at least 5 in our case

p = probability of success which is probability of Roman Catholic of

0.90 in our case

So, P(X >= 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8)

= $\binom{8}{5}0.9^{5}(1-0.9)^{8-5} + \binom{8}{6}0.9^{6}(1-0.9)^{8-6} + \binom{8}{7}0.9^{7}(1-0.9)^{8-7} + \binom{8}{8}0.9^{8}(1-0.9)^{8-8}$

= 56 * $0.9^{5} * (0.1)^{3}$ + 28 * $0.9^{6} * (0.1)^{2}$ + 8 * $0.9^{7} * (0.1)^{1}$ + 1 * $0.9^{8}$

= 0.995

Therefore, probability that the sample contains at least five Roman Catholics is 0.995.

3 0

3 years ago

The graph of f(x) shown below has the same shape as the graph of g (x) = x^2 but it is shifted to the left 2 units. what is the

mariarad [96]

Answer:

C. F(x) = (x+2)²

Step-by-step explanation:

A horizontal shift to the right by "h" units is achieved by replacing x with (x-h). The shift we want is to the left by 2 units, so h = -2, and we have ...

f(x) = g(x -(-2)) = g(x+2)

f(x) = (x+2)²

8 0

3 years ago

PLEASE HELP!! I'll make brainliest

Gekata [30.6K]

Sorry people send you links instead of actually helping you

5 0

3 years ago

Ed’s rental charges a flat fee of $5 plus $2 per hour to rent a pair of skates. A. Write an equation to model the cost of rentin

VashaNatasha [74]

The cost equation has a constant rate of change, so this is a line of the form:

y=mx+b, you are told that there is a flat fee of $5 and an hourly rate of $2 so

y=2x+5

The y-intercept (the value of y when x=0) is 5. The point (0,5) on the line.

8 0

3 years ago

Read 2 more answers

Suppose that, after measuring the duration of many telephone calls, a telephone company found their data was well-approximated b

Musya8 [376]

Answer:

a) 7.79%

b) 67.03%

c) Cumulative Distribution Function

$P(t) = \displaystyle\int^{\infty}_{-\infty} 0.1e^{-0.1t}~dt\\\\= \displaystyle\int^{b}_{a} 0.1e^{-0.1t}~dt, ~~a\leq t \leq b$

Step-by-step explanation:

We are given the following in the question:

$p(x) = 0.1 e^{-0.1x}$

where x is the duration of a call, in minutes.

a) P( calls last between 2 and 3 minutes)

$=\displaystyle\int^3_2 p(x)~ dx\\\\= \displaystyle\int^3_20.1e^{-0.1x}~dx\\\\=\Big[-e^{-0.1x}\Big]^3_2\\\\=-\Big[e^{-0.3}-e^{-0.2}\Big]\\\\= 0.0779\\=7.79\%$

b) P(calls last 4 minutes or more)

$=\displaystyle\int^{\infty}_4 p(x)~ dx\\\\= \displaystyle\int^{\infty}_40.1e^{-0.1x}~dx\\\\=\Big[-e^{-0.1x}\Big]^{\infty}_4\\\\=-\Big[e^{\infty}-e^{-0.4}\Big]\\\\=-(0- 0.6703)\\= 0.6703\\=67.03\%$

c) cumulative distribution function

$P(t) = \displaystyle\int^{\infty}_{-\infty} 0.1e^{-0.1t}~dt\\\\= \displaystyle\int^{b}_{a} 0.1e^{-0.1t}~dt, ~~a\leq t \leq b$

6 0

4 years ago