I need some help with this question

Butoxors [25]

50%. If you divide 28 by 14, (14/28), you’d get 0.5. Move the decimal place two places to the right, and that’s 50% :)

7 0

1 year ago

The daily dinner bills in a local restaurant are normally distributed with a mean of $28 and a standard deviation of $6. What ar

Degger [83]

Answer:

The minimum value of the bill that is greater than 95% of the bills is $37.87.

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

$\mu = 28, \sigma = 6$

What are the minimum value of the bill that is greater than 95% of the bills?

This is the 95th percentile, which is X when Z has a pvalue of 0.95. So X when Z = 1.645.

$Z = \frac{X - \mu}{\sigma}$

$1.645 = \frac{X - 28}{6}$

$X - 28 = 6*1.645$

$X = 37.87$

The minimum value of the bill that is greater than 95% of the bills is $37.87.

4 0

3 years ago

The circle C has centre A(2,1) and passes through the point B(10,7). Find and equation for C

Semmy [17]

The equation of a circle:
$(x-h)^2+(y-k)^2=r^2$
(h,k) - the coordinates of the centre
r - the radius

$A(2,1) - \hbox{the centre} \\
h=2 \\ k=1 \\ \\
(x-2)^2+(y-1)^2=r^2 \\ \\
\hbox{passes through B(10,7)} \\
x=10 \\
y=7 \\ \\
(10-2)^2+(7-1)^2=r^2 \\
8^2+6^2=r^2 \\
64+36=r^2 \\
r^2=100 \\ \\
\hbox{the equation:} \\ \boxed{(x-2)^2+(y-1)^2=100}$

7 0

3 years ago

Across which axis was point A reflected

Snezhnost [94]

Answer:

When point A with coordinates (0, -1) is reflected across the x-axis and mapped onto point A', the coordinates of A' will be (0, 1).

i.e A'(0, 1) is the image of point A after a reflection.

Hence, point A is reflected across the x-axis.

Step-by-step explanation:

When we reflect a point A across the x-axis, the value of 'y' gets negated, but the value of 'x' remains unchanged.

In other words, when point P with coordinates (x, y) is reflected across the x-axis and mapped onto point P', the coordinates of P' will be (x, -y).

Thus, the rule is:

P(x, y) → P'(x, -y)

Thus, when point A with coordinates (0, -1) is reflected across the x-axis and mapped onto point A', the coordinates of A' will be (0, 1).

i.e A'(0, 1) is the image of point A after a reflection.

Hence, point A is reflected across the x-axis.

4 0

2 years ago

In a standard normal distribution, about _________% of the scores fall above a z-score of 3.00

Katarina [22]

The normal rule to remember is 68-95-99.7, i.e. plus or minus three sigma corresponds to 99.7% of the probability. That leaves 0.3% in the two tails, or 0.15% in the tail above 3 sigma.

Answer: 0.15%

7 0

2 years ago