please help me. Which one is it I think it's the first one because it's not random but they all seem pretty random

Mr. Barnett’s test is normally distributed with a mean of 65 with a standard deviation of five points what is the probability th

uranmaximum [27]

Answer: 2.5%

Step-by-step explanation:

Mean score = 65

Standard deviation = 5

Score (x) = >75

Z-score = [(score - mean) ÷ standard deviation]

Z - score = [(75 - 65) ÷ 5]

Z - score = 10 ÷ 5 = 2

P(score higher than 75) = 100 - 95 = 5/2 = 2.5%

4 0

2 years ago

Over the course of the school year, you keep track of how much snow falls on a given day and whether it was a snow day. Your dat

Free_Kalibri [48]

Answer:

Probability of the day to be a snow day is 0.34

Step-by-step explanation:

We have the data,

Out of 21 which had less than 3 inches of snow, 5 were snow days.

Out of 8 days which had more than 3 inches of snow, 6 were snow days.

So, we get,

Total number of days = 21 + 8 = 29

Total number of snow days = 5 + 6 = 11

Thus, the probability that the day will be a snow day is $\frac{11}{29}$ i.e. 0.34

Hence, the probability of the day to be a snow day is 0.34.

5 0

2 years ago

If Joan reads 75 pages in 4 hours how long will it take her to read 250 pages?

uysha [10]

Answer:10 hours to read all 250 pages

Step-by-step explanation:

4 0

3 years ago

Ivanna is a software saleswoman. Let y represent her total pay (in dollars). Let x represent the number of copies of History is

artcher [175]

1. For every extra copy, Ivanna sells she gets an additional 120 dollars (+$120) and for every less copy she loses $120 dollars (-$120).

2. Ivanna's total pay is $2,400 if she doesn't sell any copies of History is Fun.

Step-by-step explanation:

Step 1:

y = 2,400 + 120x, where y is Ivanna's total pay and x is the number of copies of history is fun she sells.

To calculate the change is Ivanna's pay we find the difference in pay for two consecutive values of y.

We must calculate y when x is of consecutive values i.e. 1, 2, 3, 4 ...

Step 2:

We calculate the value of y when x = 1, 2 and 3.

When x = 1, y = 2,400 + 120 (1) = 2,400 + 120 = $2,520.

When x = 2, y = 2,400 + 120 (2) = 2,400 + 240 = $2,640.

When x = 3, y = 2,400 + 120 (3) = 2,400 + 360 = $2,760.

Step 3:

To calculate the increase in her pay for a copy, we subtract y when x = 2 from y when x = 3.

(y when x = 3) - (y when x = 2) = $2,760 - $2,640 = $120.

So for every extra copy, Ivanna gets an extra $120.

To calculate the decrease in her pay for a copy, we subtract y when x = 3 from y when x = 2.

(y when x = 2) - (y when x = 3) = $2,640 - $2,760 = -$120.

So for every less copy, Ivanna loses $120.

Step 4:

To calculate her pay when she doesn't sell any copies of history is fun, we substitute the value of x as 0 in y.

When x = 0, y = 2,400 + 120 (0) = $2,400.

So Ivanna earns $2,400 if she doesn't sell any copies of history is fun.

8 0

3 years ago

A bakery sold 111 cupcakes in one day. The head baker predicted he would sell 91 cupcakes that day. What was the percent error o

Yuliya22 [10]

$111-91=20-error\\\\\begin{array}{ccc}91&-&100\%\\\\20&-&p\%\end{array}\ \ \ |cross\ multiply\\\\\\91p=100\cdot20\\91p=2000\ \ \ \ |divide\ both\ sides\ by\ 91\\\\\boxed{p\approx21.98\ (\%)}\leftarrow answer$

3 0

3 years ago